I've got a 20 year old Fragramatic Vac/ Carpet Cleaner and I want to add a Cryptopay Card Reader to it but obviously the old timer/display is not compatible. I'm afraid to ask what an upgrade will cost so I'm considering rewiring to eliminate the large countdown timer. I'm thinking about replacing the timer with a Dixmor LED7. I understand that I lose the dual timer capability and carpet cleaner customers will love it. What are the drawbacks to this plan that I'm not seeing? thanks, jerry