No doubt you will be expecting a reply from me (and as everyone knows, I hate to disappoint) ... but I just don't have the time to do a proper analysis right now, Dave. By "analysis" I mean breaking it down into man-hours.
However, straight off the top of my head, and using my usual "rule of thumb" (based simply on the number of maintainable items listed), I would go once again for four
Specifically, a Senior Technician and three Technicians.
If that figure doesn't gel with the actual number of techs deployed, that will most likely be due to you not doing PM often enough (that is, my default PM interval is six months). By the way, these days most of my time is spent fiddling about with data, so I am always on the look-out for "real world" inventories (of biomed maintainable assets) - parts stock lists as well. If anyone has some nice data that they don't mind sharing (.xls format preferred), please feel free to bung it together with an email. Confidentiality is always respected (and thanks again to those who have already sent some stuff).