For any new controler deal with the MFG as you are doining, the company has changed hands and not as accomadating as the old company owners in maybe giving a replacement control.
As to present control and filing contacts which will disappear eventually, try some dielectric grease on contact points and see if that stops the pitting or carbon build up making filling necessary. Try on one control to see if it helps.
Try to match the control with
this link for possible replacement fix.
I had the older control with the speed dial, I think some controls are interchangeable.