I support your decision, though of course I'd go about it in a slightly different way!
First, define "typical English IPA". Modern recipes for IPA are
vastly different from the stuff that actually shipped to the Raj. Most modern Imperial IPA recipes are actually pretty close to historical IPAs, IMO.
Once you start looking at the source material, you'll find that the beers in question aren't just hoppy; they're
insanely hoppy, like 3-4 oz. per gallon hoppy. There's some interesting discussion about such characteristics of historical beers amongst beer historians. The wonderful thing is, we can brew and brew and brew and never really know if we've got it right - it's the taste-testing that makes it all worthwhile! (Well, most of the time. Some day, if you're interested, ask me about my redaction of Col. Washington's Molasses Porter.)
Reading Material:
Foster, Terry.
Pale Ale
http://strandbrewers.org/reviews/nhc2001-ipa.htm
http://www.durdenparkbeer.org.uk/index.html - where you can get an essential bit of source material for this project:
Old British Beers and How To Make Them.
Practically speaking, there's no guarantee that your proposed IPA would have had Brett at all. Brewers have been lining their casks with pitch for a long time. There's no definitive answer to the question of "lined or unlined?", historically speaking, but it's possible that casks filled with India Ale would have been internally lined with brewer's pitch, preventing in large degree the introduction of spoiling microflora.
That said, it is known that India Ales were brewed for high alcohol and high hops rates in order to prevent spoilage. But it is possible that introduction of spoiling microflora happened at a different point, such as in the racking mechanism.
Still, should you wish to introduce
Brettanomyces, allow me to suggest a method.
Use English, French or Polish oak for your cubes. First, English and French oak are appropriate, historically. Second, American oak will put
way too much oak flavor in your beer, unless you specially treat the cubes before introducing them to the wort.
Prepare a small wort (like you would a starter), a scaled-down version of your intended recipe. Ferment this in a half-gallon growler with your normal (or intended) yeast. When the
saccaromyces have finished their work, add your
Brettanomyces. Add your oak cubes at the same time. Let that work until your main batch is ready for oaking, then retrieve your cubes from the growler, steam them in some appropriate kitchen utensil - I use a vegetable steamer - and add them to your main batch[*]. Let 'em soak for as long as you like. Taste the beer periodically to sense when you've got your desired "funk"; when you're at that point, package it. Were I you, I'd get a pin (small firkin) and cask-condition it for tradition's sake. You can keg it, too. In any case, if you keg/cask it you should
not carbonate this beer beyond 1.5 volumes. Anything more is inappropriate, historically - because wooden casks, even if they're lined, leak gas from myriad orifices - and also detrimental to flavor. There is also support for bottling India Ale, but that opens up an entirely different discussion about historical bottle-conditioning practices.
Let us know how this turns out! Ain't historical brewing fun?
Cheers,
Bob
[*] Wooden casks were commonly "cleaned" with steam. Some traditional English and Belgian breweries continue use the practice. I suggest it so as to reduce the total amount of
Brettanomyces to trace levels, mimicking the exposure of India Ale to soured oak on a long sea voyage.