A couple thoughts: The old Boddington Bitter was unique in that it was fermented out to <1.000.
Well that's where it gets complicated when people start talking about Boddies' yeast, as at least three or more were used just in the course of the 20th century. There's at least one pre-WWII yeast -
in 1901 the apparent attenuation (AA) was 75%, it dropped
below 62% in January 1919 - presumably a combination of ingredient quality and attempting to retain some mouthfeel at a time when ABV was under a lot of government pressure, but was back up to 69% in 1921 and was 75-77% by the late 1930s.
After the Luftwaffe "reconfigured" the brewery in the Manchester Blitz of 22-23 December 1940, they got a new yeast in from Tadcaster that was obviously diastatic to give the bone dryness of what's now regarded as the "classic" Boddies of the 1970s.
In 1951 it was giving 87.5% AA,
in 1966 89.6% AA,
in 1971 91.6% AA,
in 1974 88.4% AA.
There's a general consensus that "Boddies went wrong" some time in the late 1970s to early 1980s and it's been claimed that they "lost the yeast" around that time and replaced it with another one, and/or "cleaned up" the yeast -which is plausible, a lot of family brewers did that in the 1970s.
Boak and Bailey have a
good article/comments on the subject. It's complicated, but the core of it seems to have been that after lager exploded in popularity during the droughts of 1975/6, management made a concerted effort to reduce the characteristic dryness and bitterness to make it more palatable to the majority. They weren't the only ones - perhaps the most famous example was the replacement of Red Barrel with the much blander Watney Red in 1971. Some of this was through process changes, so it's not clear whether a new yeast was involved. There were also changes forced on them, like Tate & Lyle ending production of one of the sugars used (presumably due to the changes in the sugar industry around the time of our entry to the EEC in the mid 1970s) which may be the reason it apparently got a little darker. And the pressures of recession may have been behind the switch from "classic malting varieties" in 1980 to Triumph barley "
of which many brewers privately are scathing".
General thought seems to be that the changes started around 1976 with a particularly obvious change in around 1981/2, but it's worth noting that Ron has an apparent attenuation of 83.6%
in 1987, by which time they'd dropped all the adjuncts in the recipe bar a smidge of invert presumably to adjust the gravity for consistency. So given that we know they'd changed the process and recipe, it feels like they probably hadn't completely changed the yeast.
Then in 1989 Whitbread took them over (having first bought a 13% stake in 1961). Some obvious things to say - Whitbread were based in London, had one of the biggest yeast libraries in the world, had two strains that have become widespread in British brewing, and had several breweries around the UK.
Boddies became huge in the UK in the 1990s thanks to smart advertising, Whitbread's distribution and nitro "widget" cans. They tried brand extensions, including a stronger Export which didn't last long here but AIUI is what is still sold Stateside as Pub Ale. Pub Ale is different to the stuff we're talking about here which is Boddington's Bitter. In November 2003 the cask version was
rebranded as Boddington's Cask with the ABV tweaked from 3.8% to 4.1%, wheat malt dropped to leave it all-barley malt, and
reportedly drier and more bitter again. Was that a process change or was it a yeast change? Had Whitbread switched to one of their yeasts in the 1990s?????
But in 2000 Whitbread sold to Interbrew (which became AB InBev) who closed down the Strangeways brewery in 2005. They moved keg and smallpack production to the former Whitbread greenfield breweries at Samlesbury in Lancashire and Magor in South Wales, and the Tennent's Wellpark brewery in Glasgow (bought from Bass). By that stage cask was <10% of production and was contracted out to Hyde's to keep it in Manchester, but the contract ended in 2012 and that was the end of cask Boddies. Supposedly they ended up using the Hyde's yeast because "the Boddies yeast fell apart at Hyde's and there was too much wastage". That sounds like a multistrain failing to adapt - possibly a switch from open fermenters to conicals?????
We also know from sequencing that 1318 and 1945 NeoBritannia are close relatives, and both are almost as closely related to 1098 and WLP017 Whitbread II. This is a key point I think.
Also we know that for most of the time that strains were being harvested that ended up in US lab collections, Boddies was either owned by Whitbread or brewed at a Whitbread brewery under Interbrew ownership. To me this confusion about London Ale III being linked to Boddies must be down to a version of Boddies that was brewed with Whitbread yeast. Maybe they used Whitbread yeast at Strangeways during the 1990s, maybe someone managed to harvest some (or source some direct from the brewery) from Samlesbury/Magor/Wellpark after Strangeways closed. My current guess - and that's all it is - is that Export/Pub Ale is/was brewed with Whitbread yeast which to a US collector would be "the" Boddington yeast, and/or if someone asked Wellpark for "the Boddington yeast" they were probably using the Whitbread yeast for all their ales (since it's mainly a lager brewery).
All speculation at this point, but the murk is beginning to clear a little I think.
I take that back. WLP085 for example is fantastic (it's WLP02 and 07? mixed), flocculates like a cottage cheese, is very clean, and avoids the overly sweetness of 02. (I only got it because I did a 15 minute drive by of White Labs in San Diego 18 months ago, and it's been stuck in the vault with only 2 orders for months). It should be a standard offering. Yorkshire Squares, on the other hand, is beyond my modest ability. Furthermore, I found that the 100+ lab hours spent on WLP611/Torulaspora delbrueckii didn't help humanity much. 
