In regard to Lot 1087, the side plate is very similar to Grinslade's NE47, as is the triggerguard.
I like this fowler (Morphy's) but I believe that is obviously, in light of the post 1813 Birmingham proofs, 1st quarter 19th Century. Check out Joe Puleo's Ketland article in Vol 33, No 6 2011 Man at Arms Magazine.