I believe JA stands for James, and I have three James Tirrells from Massachusetts who were born in the right timeframe to have provided service in the Revolutionary War. I checked the DAR Patriot Index and there are no James Tirrells listed, but that only means that no descendant has joined the DAR through that lineage. Here's the particulars: James b. 19 Dec 1752, Abington, MA; James b. 8 Aug 1762, Weymouth, MA, d. 25 Jun 1826; James b. 1 Mar 1768, Weymouth, d. 27 May 1815, Weymouth. I have more information if you're interested.
Karen