My FAA license is standalone
Under some circumstances you can fly N-registered airplanes in the UK with the FAA certificate. This DOES require a medical.
but wanted to revalidate it in the USA first.
There is no such thing as "revalidation" in the European sense. The certificate is valid forever. Various currency requirements must be met.
Things to consider - do you still have an old paper certificate, or is it plastic? Have you moved since you got it?
just fly on the FAA license with an instructor.
You can do a flight review and become 90-day current with a flight instructor. Everything about your certificate would then be up-to-date except you couldn't fly solo or take passengers
I'd heard they were talking about removing the medical for private pilots.
As linked above, it's already the law
Specifics on implementation are pending, but the time for that is limited.
I'm not too sure how to get a CAA license starting with what you have, but many people in the UK do it. I did it in Germany (and am now stuck with Germany because the privacy laws that are to protect my data won't let me direct that my data be sent to the UK or elsewhere. Unintended consequence?)
Thanks!