If this is stylus/canti. only, a reasonably priced digital microscope has been used by many. If it's internal. there are a number of companies, both here and across the channel. N.W. Analogue (Dominic?) is one such here, but ESCo will inspect for a reasonable sum and deduct that from the invoice if they do any work considered necessary, I believe. Just wouldn't fancy their stick-on Paratrace tip, though. I assume it's a fairly high-end cart.