I haven't voted, mostly because the way the question is posed, it is hard to know what the results mean. If you have a community of folks who are using 40 year-old cameras, what does it mean that a shutter needs a tune up?
For example, in general, all of my cameras are reliable. I have a shutter tester that lets me measure the accuracy and repeatability of most of the shutters in most of the cameras I own (the LTM Leicas being the the big exceptions). More useful information would be something like the mean time between failures of your cameras. With Leica M's it seems to run in decades (two shutter replacements and one circuit board out of 8 M's over 20 years, 6 of which I still own). With Nikons it is about the same (one shutter replacement (F4) between 1991 and 2010 out of 7 cameras, all but one of which I still own). One Rolleiflex with a jammed film transport out of 2 cameras owned for 15 years. One jammed Hassleblad lens out of three bodies and five lenses over 25 years. Oh and a Hassie wide with a slow 1 sec shutter. Cameras that have never broken: Two Pentax K1000s over five years; one Pentax LX over three years (although the rewind crank fell off once and got lost); Pentax 67: one body four lenses over 25 years, numerous LF cameras and lenses over 20 years (although I did have a sticky Linhoff/Compur shutter that was 35 years old cleaned) and a Wisner 5x7 that arrived new from Ron Wisner all fouled up; 6x7, 6x4.5 Fuji rangefinders, Olympus Pen, etc. etc. You see where I am going with this? Without plotting the failures on a time axis, or knowing how many cameras the responder has, what does it mean that foam seals are the most common complaint? If I own only 1 camera and the only thing that goes wrong with it in 40 years is that the foam seals need replacing once, it hardly means that the camera is unreliable or that the foam was defective. Similarly, if you have more cameras than sense (as I do) and you aren't using the gear enough to stress it, a lack of repairs doesn't necessarily mean that the gear is reliable, it just means that you aren't getting anywhere near the equipment's failure rate (and aren't likely to).
Ben Marks