The bridge cover is 'as fit's' I'm afraid - but it's rather obviated by the size and position of the actual bridge itself. The rear corners of the bridge may be only a few thousandths clearance though when it's right.
Be careful here - there are a FEW older Ps that have wider bridges and will not accept a cover at all - and I have one of them:::
and I was frustrated but found a new home for the P-bridge cover I bought.
Now - the p'up cover is another thing and I have drawings and dimensions if you want them on a PDF printable file.
let me know
FYI: ALL P-basses will have the same dimension for the guard.
Center-to-center of the screws is exactly: 4.625" - so it's gonna take a little compression of the guard to fit it correctly.
This 'compressing' the guard is normal as the package has prolly been sat upon and kicked around the shipping house floor for a while and it is prolly distorted a tad bit.
Don't make a big mistake and install it as it sits, as you may have it sitting directly on the strings if it's bent flat badly enough.
One COULD eyeball it if one paid attention to the actual center of the screws that need to go into the PG and body.