Bowcaster Parts

[ATAUK]

Came across this and unsure what this would be called but is a barrel mount of sorts
. Too wide i know but close

 

[ATAUK]

Also wondering if any one has identified the correct size screws on the side plates and dials . Were there 2 different sizes and has the screw type been confirmed

Webbing / leather or alumium on the rear of the stock for attaching the slings ?

Any one have the Trigger disc dimensions ?