The whole lower slide is Mk2. there should be a projection forward of the front tripod mount for a Mk1. This looks like a Inglis Mk2 complete lower assembly. Also the mag catch is mk2, the Mk1 dosn't have a hole through it.
The whole lower slide is Mk2. there should be a projection forward of the front tripod mount for a Mk1. This looks like a Inglis Mk2 complete lower assembly. Also the mag catch is mk2, the Mk1 dosn't have a hole through it.