I would personally talk to your local sandblasting or electroplating shop and ask an industry pro their advice. Blasting is likely to be too rough but there are some soft blasting media out there (made of plastic) that may well do the job, not sure. If they don't have any good advice you've established contacts who can strip and re-plate your fork!

I had a similar problem trying to preserve the chrome under a frame I was repainting last year but eventually decided it wasn't worth the headache.