Can you help me identify this old bike?
the BSA 1.37" on the BB lockring is for British Standard (association?) more commonly noted as BSC, for British Standard Cycle.  I know these can be swapped out, but looking at the grip shifter and Nexus rear hub, those were early 80's-current, the crank is made to look like a cottered crank, but it's cotterless.  I'm going to say this is more modern than it's pretending to be, grease nipple notwithstanding.  I don't personally know the last time Brooks made that "hat pin" seat...  Just some reference points to look at.