I have the Middlesex Village 1756 Sea Service.It's similiar to yours.
The lock is OK,but slower than a Siler.I had a front sight installed and replaced the wooden ramrod with a synthetic one.I've been using ~50gr FFg Goex with equivalent volume of shot or a roundball from .570 to .600 so far.Not wonderful,but it'll suffice-and it was cheaper than some others.
I'll be trying it for grouse and rabbits in winter.