I'll try that later. I *just* moved all of mine out of my lab, and don't really want to hook that all up again. I have a plan of having up 5 at a time and do some comparisons, so I'll do that as one of my tests.
If you need some oddball parts, if it's small, it may be feasible to ship that part to you. Keeping an equipment of this vintage takes a community, so I'll be happy to offer whatever I can. I'm not really thinking of charging beyond shipping and enough for my supplies, so please - let me know if I can help. If you want that transformer, however, you are on your own.
One of my monitors is stupid sharp. That one is labeled "OPT 462 Impulse Bandwidth Spectrum Analyzer" where others are labeled "Spectrum Analyzer Display". I was going to investigate this but I haven't yet. I *think* it has something to do with EMI testing.
I'm thinking your 8568B is quite pleased he/she is in such a demand. I have an equipment like that but mine is quite a basic stuff. Analog VOM. I bought it when I was in 7th grade. I still have it. It is still here despite at one occasion, a user (ME) almost died working with it in tube equipment. When I worked in Japan as a tech, the company borrowed an Anritsu SP+TG unit from one of its clients. I don't recall the model. Royal treatment is right. It was quite needed but the company didn't have enough to buy one of its own.
That got me wanting one and I finally have one. (a FAMILY of HPs!)
I also have an HP8591EM. I've been wanting to do a comparison with HP8568B. I have a pair that's calibrated, so that would be the one to use. I'm kind of liking 8568B better. I quite don't like those push here, cycle through and push this and that - kind of UI.
Maybe you know this one. I took out two kinds of OCXO. One is by OVENAIRE and model OSC 49-61C. The other is HP10811 OSC series 3010. It also has a sticker that reads "UPGRADED TO SERIES 3010". I wonder what this mean? Simon who has a blog says they are about equal. But seems "upgraded" to certain series is something special. By the way, former is damaged. So I'm about to open it up and see what's going on. Something is lose inside and I can hear it by shaking it.