My REF 250 power amps were out of warranty and the replaced the faulty capacitors with the latest and greatest and also upgraded the internal wiring to the SE caps and internal wiring for no cost. The only difference between my REF 250s and 250SEs now are the KT150 tubes.
They also have replaced blown tubes for me at no cost many times and when I needed complete sets of replacement tubes for other Audio Research equipment, I had no problem with them.
I would be very surprised if they lost a remote and refused to replace it.
enjoy