The number wheels should be on a stainless axle with a pressed on retainer of brass or bronze. With clean hands, very gently move the retainer over about 1/16" or so, alllowing you to rotate each wheel by sliding from it's indexing pins. Start with the 10,000s 1st, then 1,000s, etc, until they all read zero. Use a 1/4 drive socket of proper size to the axle/retainer side, and VERY GENTLY tap the retainer in place with the other end of the axle on a firm surface, checking as you go for proper "tension" on the wheels. Qualify your work by rolling a mile or 2 on by hand and re-install. Job done. By the way, I've never found one that will spin backwards for more than 5/10 of a mile. Good luck with it.
I wouldn't get all bent about the legality as long as title protocals are followed.
