The SMK SYNSG is a copy of these I believe....and they are very easy to work on.
I would guess the internals are therefore identical .....but stand to be corrected.
Will @ Woodfield GunCare.....does the kit for the SYNSG....maybe give him a call or check out his site. www.woodfield-gcp.co.uk

Hes a top bloke, and will be happy to advise.

Hope this helps
Degs