ignition box repair

[chevyart]

i have been using the mallory HY-Fire 5 ignition box(with rev limiter in my nova drag car since the 90s. this was mallorys top of line box(along with comp 9000 distributor) in the 80s and early 90s. i have 2 spare boxes and 3 spare distributors) i intend to use they parts in my vega real soon. had box back to mallory 2 times in the past to repair the rev limiter and one other isue. these boxes really work nice and i even have the mallory stutter box hooked up.had trouble with the box last 2 times out and car wouldnt run and started missing. (less RPMs with each run and then the bad missing last time out). gonna disconnect the rev limiter and run car . if problem was rev limiter, then the car will run fine and i know what problem is. new problem is that mallory will not make repairs to these boxes. they say they no longer have the parts./Does anyone one of you guys out there have a company that i could contact to see if they can work on these old mallory boxes. maybe it has to be mallory company(specifiic) to fix the boxes?. any help would be appreciated thanks art