MPS, Rebuilding the MPS Options

[Ron914]

Hello to all who have helped me with this project . @emerygt350 ,@TJB/914, @Superhawk996 , @ChrisFoley , @rjames , @MDTerp
I am in the middle of rebuilding my MPS and have a couple of comments and questions .
First when I opened up the unit I found the most difficult job was removing the rivets holding the two halves together.
When I removed the retainer plate to take out the old diaphragm it was in two pieces .

I needed to take two measurements since I was replacing the stop screw , I needed to measure the the stop screw protrusion into the housing . The instruction sheet sent to me by a member had the measurements he must have made when rebuilding his MPS . His stop screw protrusion was 1.97mm and mine only measured 1.72mm.
His inner/outer screw assembly depth in the old diaphragm measured 6.51mm .
Here's one of my questions ?
when I measured mine I got two measurements depth to inner/outer screw assembly was 4.03
and depth to the washer outside the inner/outer screw assembly was 5.46mm.
Again there is a difference and since mine was never accessed before (epoxy over screw was not disturbed) is the difference in measurements ok and which measurement should I use I will try to attach a photo or two to help with my question.
this one .

I have not touched either of these measurements yet and awaiting any help/comments.
I think it's this one to the washer on diaphragm .

[ChrisFoley]

Problem with the old square o-ring is that it will have shrunk enough by now to not be any better than a new round one.

[Ron914]

Problem with the old square o-ring is that it will have shrunk enough by now to not be any better than a new round one.

@Chris Foley, @emerygt350 , @Superhawk996 , @MDTerp
I put a little dielectric grease on the old square ring and I am now showing a couple of hours for total bleed down . I think I will disassemble the complete MPS and start over since I and not getting the correct amount of deflection on the hex tool when I add vacuum from 4-7inHg to create my curve. I will also put a little of the dielectric grease on the small ring on the inner/outrer screw .The measurements I took for my full load stop screw was 1.72mm and my inner/outer screw was 5.46mm . The copy of @MDTerp 's instructions he sent showed his measurements as 1.97mm /Full load stop screw & 6.51mm for inner /outer screw.
I am hoping for better leak down results and then I will try my bench testing for my curve next .