I have an opportunity to pick up a Beseler 45 with an Ilford Multigrade 500H head, with the probe/analyzer, power supply and the 500C controller, and I have a few questions for those in the know: Can this unit be used on other enlargers, or only the Beseler? (I assume various adapters were made, but like to confirm.) Are the bulbs easy to replace? Are there any known issues as far as parts that wear out or break and can no longer be found? Thanks!