Originally Posted by Poindexter
My understanding is MO is a varietal of 2 row just like Silver Queen is a varietal or subspecies or whatever of sweet corn as distinct from field corn.
Yes, I think you're right. What I meant to say was that when 2-row is required in a British recipe, most folk would use Maris Otter for 100% of the grain bill, unless a particular speciality grain was required. There aren't that many varieties of barley that grow in the UK (we don't have any 6-row at all, and I think only have winter varieties of 2-row) so the only grain available would be MO or something pretty similar like Golden Promise. Google actually suggests MO was introduced in 1966, so it won't be absolutely historically accurate - but I think the changes in malt brought about by selective breeding were more to make the harvesting easier, rather than to change the flavor, so I'm sure it'd do the job well.
I've had a look through Radical Brewing and although there's some nice stuff on IPAs, it seems a little more inventive and a little less historically accurate than the stuff I was thinking of. I suspect I've got it confused with Designing Great Beers. As the_bird says, that'd be worth a read. But either way, good luck with it. It sounds a great project