UK Voltage from US Socket??
I noticed you're all talking about the amperage capability of the circuit and the fuse rating. I don't think a vacuum cleaner is ever going to draw that much current, so I don't think the fuses are the main issue.
Isn't the voltage also important? There's a lot of information about the US dryer circuits over on automaticwasher.org. I'm in Australia, where 240V, single phase is the stanard. Maybe I have it wrong, but my understanding is that the US "220" volt dryer circuit is actually two 120V phases cabled through a common plug with common "neutral" connector. You're essentially getting the capacity of two separate 110V circuits through a single plug/cord combination. I therefore can't think how you could wire the US 220V recepticle in a way that would deliver 220V to anything. My hunch is that at best you'll end up with 110V available for your vintage vac, which is just the same as plugging it into an standard US domestic socket.
If I have this all wrong (which is certainly on the cards), could somebody explain how the US dryer circuits really work? I've assumed you're actually using one phase to drive the motor and maybe a small heating element, and the other to drive a second, larger element, giving heaps of energy available to achieve a quick drying time.