As a rule of thumb I'd say, if a previous owner didn't mention it, it hadn't been done, especially if it hadn't been converted to silver oxide batteries. No reputable repairsman would service the prism without converting the meter at the same time. The other way round it works as well. If it had been converted to silver oxide batteries, there's a good chance the goo is gone, as no one would leave it there once the housing is removed.
Originally Posted by dsmccrac