Hi,
Unfortunately, there is no pattern of Brown Bess issued to British troops, except possibly the marine and militia musket, that bridges the F&I war and Rev war. The pattern 1756 long land was not issued in time to serve in America during the F&I war but it was the most common musket issued to British troops during the first 2 years of the Rev war and was still made until 1791. It was also the main gun issued to loyalists and it also armed many patriot troops. On the patriot side there could be some old pattern 1742 long lands still in useable condition in colonial stores or in private ownership (stolen from the crown) so that pattern gun could bridge the two wars with American troops. With the exception of the marine and militia musket, short lands did not start to show up among British troops until 1774 at the earliest. Although the gun was the pattern 1769 short land, ordnance always issued older guns in store first before sending out new patterns. The pattern dates indicate the year a pattern was accepted and production begun, not when they were issued They had plenty of long lands in store at the beginning of the war so those got issued first. The first big slug of short lands came in spring 1776 among troops sent to relieve Quebec City. Those were labeled "Dublin Castle". However, even then, the commander of the 24th foot demanded long lands and even delayed sailing for America to get them. Another slug came with some troops sent to capture Charleston in 1776. Despite those regiments, the majority of British troops had long lands until 1777 or so. On the patriot side there would be very few short lands until much later in the war. They would come from captured ships and battlefield acquisitions.
So the pattern 1756 long land with a lock simply marked "TOWER" and no date on the tail would be a good choice for patriots and British reenactors for much of the Rev War. Although it was not used during the F&I war, it still looks a lot more authentic than any of the repro short lands carried by so many F&I reenactors today. Regardless of pattern, the musket if made authentically, will be about 1-1.5 lbs heavier than your Pedersolis and Mirokus and much bigger in all dimensions. I am sure Jim will do a great job on it and with his production methods, I suspect he could eventually produce both short and long lands without a lot of extra tooling. He will turn the Brown Bess market on its head, which will be a good thing, long overdue.
dave