It has
> been suggested that Mexico is the place to get good bodywork done
> inexpensively and I would like to get some seam rust fixed while there.

I don't know much about rust fixing, and sure you can get lots of things
cheap in Mexico... but as everywhere else... buyer beware... make sure you
know how the job should be done... communicate that... and verify during the
process that it is being done...

As with any paint job... it's very tempting for the vendor to cut corners on
the preparation and cover his sins with some paint... especially when he
knows the customer is unlikely to ever come back  :)
This is saying noting about Mexicans... just human nature...

Bill