On a CA M24 you can take off the cap at the end and thus reveal some threads. There is an adaptor that goes on to that and offers you some 14mm threads if I'm correct. Now if the PSG-1 has 14mm threads you can get the M82 flash hider (
http://www.wgcshop.com/pcart/shopper...M82T_cat_Flash Hiders) so that would basically give you something similar to what you are looking for without having to pay too much. Also, the outer barrel of the CA M24 is made of pot metal.
EDIT: Here's the adaptor taken from the Silencer thread:
http://redwolfairsoft.com/redwolf/ai...l?prodID=18367