Have never seen a staking on the attachment knob like that

Hinge pin on the mount - the ends should be rounded - can not tell

If the T37 has a casting ridge around the clearance for the cylinder lock screw then it is a fake T-37

a D barrel will have a 555 in the drawing number

the 6-53 on the pad looks odd - like it was hand drawn

Are there any marks on the receiver leg?

Many will not value a undocumented M1D