I've joined the "rack-mount HP test equipment" club. Got a 3455A for US$60 off of craigslist. Seems to be in good nick for something old enough to be both affordable and "Made in the USA": front and rear binding posts are not chipped or cracked, fan bearings aren't screaming, fan filter is all there, button lights are 100%, side straps look good. Most of the rest of my used test equipment looks like it has been dragged in a sack down the stairs of the Burj Kalifa. I don't have a good way to evaluate the accuracy of a 6 1/2 digit meter, but the first 4 digits match my Fluke 179 which is a good omen. Previous owner claimed that he hadn't been in it. I was going to clean it up inside but my Phillips #2 didn't fit the case screw right so now I've got a Pozidriv bit set on the way. I'm surprised that I've been able to ignore JIS and Pozidriv for this many decades
I understand the fan on the 3455A is unobtainium. Display looks goofy in the picture due to scan-rate mismatch but it's bright and all digits light up with human persistence of vision enabled. Looks like I can't put off building my bench shelf anymore.