Your best bet is to check out Calguns for current info. I am not a lawyer and this is not legal advice.
On the mr556 I would swap the FH to a compensator, pin the stock (this can be done elegantly) or swap for a fixed, and add a Kydex wrap to get rid of the pistol grip.
I would use a Kydex wrap on the usc and sl8.
SR9TC is tough because the grip and stock make it, but swapping the wood grip (not trigger) and stock for for plain old fixed 91 furniture and adding Kydex would do it, however I just left mine in NC.
No clue on the .22
I would talk to a CA FFL that deals in this stuff. Coyote Point Armory in Bay Area knows their Hk’s if you are headed that way. Fix it all before you enter the state though.