I recently got a Racal 1996 counter (options 01 & 4E) for about $99. It was in pristine shape, but of course, almost all of the buttons were junk (I own several other Racals, all working good).
I decided, finally, to replace all of the buttons. I ordered the buttons, then kept putting it off--since I hate the thought of desoldering 40 buttons.
Then I had a Great idea--I set up my electronic solder tweezers to match the spacing of the switch leads (see photo). Since it awkward to pull switches without 3 hands, it is MUCH better to put the tweezers in a vise & move the board around to heat the desired switch--heating both leads together, lets you yank out the switch in about 8 seconds. I pulled all of the switches in record time.
Now the 80 holes were kinda clogged up. I broke out my vacuum desoldering "iron" and sucked out a pile of via solder in about 15 minutes.
Then I installed the switches which fit in place perfectly---they were the same size, shape & lead spacing. Put in about 6 switches (about as many as I could and flip the board), tacked soldered one lead so they wouldn't fall out, then when back, melted & fully seated each switch & soldered the 2nd leads of each. Important each switch is flush to the PCB. Repeated this process, till all were in. They all have a nice detent "click" like the originals.
I did some cleanup & reassembly. Since the "T-shaped" stalk on these switches is slightly thinner than the Racal version, the switch caps fit great, but would somewhat easily fall off. I used a drop of automotive weatherstrip glue to keep each in place. I wanted something tacky/sticky...not a "hard" glue that would eventually crack & fall apart from all the pressing.
The finished result looks as good as new!