Welcome to the forum and congrats on you new Pearson 26! As you probably figured out it appears your boat is a 1978 P26 One-Design #65.
The
-L is most likely an indicator that it was built in
League City Texas. This is based on information at Sailboatdata.com and from a document on P26-OD #182 that indicates it was built in League City also.
Good luck with your galley, it looks like it was an optional feature on your boat, perhaps there are some photos out there that someone will share.
A couple relative links if you have not found them: