Gotta give AutoMeter a little plug here..
sorry you're speedo quit .. but,
I have used AutoMeter for lots of projects and one of those was a front engine nostalgia alcohol dragster. (AutoMeter HQ is a few minutes from my house, that's why i started using their stuff!)
After a run at Indy, the $$ memory tach, with a magneto conversion went south. I went into their lobby at lunch time one day and asked if I could drop it off for repair. The gal said wait I'll get a tech.... A nice young fella came out and asked if I could wait a few minutes. Unbelievably he came out with a brand new tach and the expensive magneto set up for me. He said they wanted to bench the one bought in " sorry for any inconvenience"!
No "when did you buy it" or "did you register it?" stuff; just handed me a new piece and his business card if I had any trouble. So, I continue to patronize those guys...
I did the same thing as Squire. I used the stock bevels to convert my 5" gauges also. That'll work. Looks good that way too.
Unfortunately, I need to pull my brand new Autometer speedometer out again after all that trouble because it doesn't work. It needs to go back to the factory to repair.
My guess is Autometer is beginning to use Chinese electronic components or maybe getting their entire gauges made there.