Thanks! I was very pleasantly surprised with how well the front panel cleaned up. Some patient rubbing with denatured alcohol soaked paper towels did an excellent job of removing the black marker, and the knobs cleaned up nicely with a good soaking with Windex wetted paper towels. The downside is that that usually removes the painted pointers from the knobs. The voltage ones were pretty easy to redo, as the 'pointer' spot is recessed slightly, so a dab of paint and then a skimming with a toothpick or popsicle stick will clean the excess nicely. The one used for the meter range switch, on the other hand... Its pointer is slightly raised, and it was a battle to get the paint on it and clean the excess off under the microscope using toothpick. I've had good success with that kind of knob in the past, but last night just didn't have the touch - it took about three or four tries, and I'm still not completely happy with it.
A close look showed that the badges are just glued in place, and the two holes are only for some little alignment nubs, not retaining posts as I'd originally thought (but never bothered to actually check), so it's a bit less of a surprise that they're so often missing - probably doesn't take much to wipe one off if the adhesive gets old and brittle as that seems to be all that's holding it on. (I still want to find a case of NOS ones, nonetheless!!)
I don't have too much experience (yet) with this series, but plan to keep an eye out for some more of them. There's also a 6024A in the queue; I got it cheap a while back as it seemed to be dead, showing a current limit light whenever it was powered up. Turns out the current limit pot was set too low, and the voltmeter movement is sticky. Tweaking the I limit pot up got the current limit light to shut off and voltage to emerge from the terminals, but the voltage meter, she no work. I plan to take the meter apart in an effort to free it up; failing that I suppose I could put a digital readout in there. I'd like to keep it as original as possible, though, as it's a 200W supply and the current capabilities drop off as the voltage goes up, and the current limits vs voltage are shown on the meter (and the V vs I ones are shown on the ammeter). That one maxes out at 10A@20V, sliding down to 3.3A@60V
HP certainly did a lot of creative things to make good, reliable power supplies, didn't they?
-Pat