Nick, I've been looking for a good Boston Ale clone recipe myself. Here is one that I found that may be similar to what you are looking at:
7.75 lbs Pale LME
1.00 lb crystal 10L steeped for about thirty minutes.
1.5 ounces of East Kent Goldings for 60 minutes
0.5 ounces of saaz for 15 minutes
0.5 ounces of saaz for 5 minutes
0.5 ounces of cascade for 5 minutes
Safale ale yeast
source:
http://www.skotrat.com/skotrat/recipes/ale/american/recipes/39.html
And here is another that I'm planning to try. It is based on a partial mash that I found on the web then converted to extract with steeping using BeerSmith. The end result is:
3.07 lb extra light DME
4.27 lb pale LME
0.68 lb crystal malt 60L
2.0 oz spalter (5.3%) - 60 min
0.5 oz East Kent Goldings (6.0%) - 30 min
0.5 oz East Kent Goldings (6.0%) - 10 min
1.0 oz Fuggles (4.5%) - 0 min
yeast: East Coast Ale (White Labs #WLP008)
Gives 31.5 IBU and 10.3 SRM.
I'm planning on trying this last recipe for my next batch, although I'll probably use Safale dry yeast instead of the one specified.
If you get a good result with your clone, please post it.