I installed what I think was the Pertronix Ignitor on my 56 Victoria about 50,000 miles ago and have enjoyed not having. to reach way back in the engine bay to change points and condenser. I run a stock 292 with a later 450 cfm Holley 4 barrel and hand choke.. I kept the original coil and external resistor. I have enjoyed the set up other than hard starts on cold mornings. It seems odd to me that the motor more often than not, will fire only after I release the key from the start position to the on position. And if it doesn't fire off the vacuum wipers will jump in place occasionally. Shouldn't the motor fire in the start position? . 

Geo56, if your Pertronix 1 lasted 15 years+, I would say that you got your money's worth. A family member has had a Pertronix 1 in his 65 Mustangs for years without issues. You might consider replacing it with the Pertronix ll, if it's time, but the Pertronix lll, I don't think, is compatible with the 57 distributor.