CAI used to sell modified m59/66s for california. they no longer do so. to be honest with you the one i had kind of sucked. it was way too heavy in front, and the heavy muzzle brake made it worse.
i have two skses, an m59 and a chinese paratrooper. both are excellent and handle far better than the 59/66. honestly i have no idea what the yugos were thinking when they issued that "upgrade". They basically took a smooth carbine and turned it into a clunky rock chucker.
if you want a grenade launcher in your fire squad... bring an mk69. dont futz with the rifle..