MPS Spacer - I'm confused,, and that's happening more often lately! Options

[adolimpio]

My 2.0 started stumbling lately and checked all of the usual suspects, including MPS leak down and seemed to be perfect. After spending some time reading through various posting I found numerous references to MPS diaphragm issues even though they tested ok, so I opened mine and found that the diaphragm was indeed cracked.

I have 2 1.7 MPS which also test OK, so I decided to open them to see if I could salvage their diaphragm, but just like the 2.0, they were both cracked even though they tested ok.

What confused me is that all 3 had the spacer intended for 2.0s. The 2.0 was a 037 and both 1.7s were 049s and all had rivets intact so they had not been opened.

I measure the thickness of all 3 at 0.024, and a picture is shown below. Do I have it correct, is this the spacer intended to provide more latitude for adjustment in 2.0s? Any idea why they would have been in 049s?

I guess the issue with testing Ok, but still being cracked makes buying a used MPS that states "holds vacuum" risky. Being 50 years old, we should probably assume that used one will need to be rebuilt.