AC adapter? Amp w/UK plug how to use in the US

I have a vintage British amp and it has a UK AC plug. I have been unsuccessful at finding a good quality (cryogenically treated preferred) plug adapter. I have found many U.S. AC Plug to U.K. adapters but I need one in reverse of that.

can anyone out there point me in a direction?

Another possibility; My amp can switch voltage but it's cable is hardwired. Would it be advisable just to have the amp rewired with a quality cable and US plug? and is there anyone in the LA area who could accomplish that?

Thanks a bunch. I can't wait to get power to this thing and turn it on.
If your amp can switch voltage, you can cut the UK plug off your present good power cable (assuming it is excellent) and rewire the cable to a US plug (find an excellent grade one). For cheaper or faster resolution, you can get a universal adapter from Radio Shack. Hope this helps!