I've two pairs of binoculars that need to be re-aligned- the prisms have moved a little.

Is there anywhere in Chiang Mai that can do that sort of job? It isn't a DIY job, I've tried

To answer my own question - just for the record-

Shop on Ratwithi, inside the moat. Between UN pub and Moon Muang (same side) near Moon Muang. Shop with 'camera repair' sign.

The repair was not perfect nor cheap, 500 baht to re-align the prisms. Still cheaper than a new pair.