This arrived in the mail today:
I had a partially working A500 keyboard that I diagnosed to have only a faulty membrane, after testing the keyboard controller on another, known working membrane and keyset. I have used the sellmyretro.com membranes multiple times, and they work OK, but, since I did not have one on hand, I decided to get one of these, despite the high price they are being sold for on ebay by the manufacturer. Also, since it can be used interchangeably with an A1200 keyboard, via a ribbon cable instead of the A500's keyboard controller, it is a versatile product. It was designed originally by a few members of the Polish Amiga forum (PPA.pl).
It works well, but, you will have to use a surprising amount of force to carefully connect it to the keyboard controller's connector, which is usually engaging a paper-thin membrane, versus a 0.4 mm thick PCB. Would I buy it again? Probably not, due to the high cost and then the shipping from the UK.