Wells Gardner monitor pincushion issue + ID request

[Shaddycat]

Hey all,

I've got a Ridge Racer cabinet that I just inherited.  Hasn't been on for a while.  Just got it spun up and it seems to have a bit of a pincushion issue.  The sides are collapsed in a fair little bit.  I can't seem to spot a pincushion pot on it anywhere though.  I also haven't had any luck identifying this monitor to find any sort of schematics or manual.  I am pretty sure this is not the same monitor that came with the cabinet originally.  Can anyone please help me identify this monitor and maybe point me in the direction of fixing the pincushion issue?

https://imgur.com/a/tFQeLBM - Images of the chassis + the pincushion issue.

[Shaddycat]

Bump: Found the pincushion pot.  But even after adjusting it to what is as close to perfect as I can, it still seems to bend/bow in the corners.  I also cannot seem to increase the horizontal size to fill the whole screen.  Anyone have any suggestions?