My home table GC3 - acquired recently- was most probably a tournament table at one time based on the decals on the table - it has 4.75 inch pockets- not 5 inch pockets. The slate shelves for the pockets are more forgiving than Diamond table pocket shelves. This allows more balls to fall into the pockets that would definitely stay up on a Diamond or Rasson table ( I have played on both).If the table looks as good as that corner casting, you may want to jump on it. If it's a tournament edition, it could be 4.75", but it looks like 5.

Looks just like my gc4 did.The pocket facings look a little strange. Like wavy. But I agree that based on the balls in the pocket, that's 5 inch, or close to it.
I have a 9' Diamond Paragon with 4.75" pockets. I'm 72 and wanted to still enjoy pocketing balls. I thought that extra quarter-inch might help as I aged.Working with someone on FB marketplace so I can't measure it myself. Their tape measurement is crooked but I got the ball pic.
This is a gc4.
Does it look like factory standard 5" corners?
You have the right idea. Pool is about enjoyment. And yes, his table looks like a bog standard GC (5 inch pocket), it will probably be easier than yours, if for no other reason that the shelf is more shallow on the GC but the opening being larger will also contribute.I have a 9' Diamond Paragon with 4.75" pockets. I'm 72 and wanted to still enjoy pocketing balls. I thought that extra quarter-inch might help as I aged.
The pockets on the table in your picture appear to be 4.75" at the points. However, they don't appear to narrow much, if at all, at the rear of the shelf. Mine are 4.5" at the rear of the shelf, which is think is a decent pocket for an older person's home table. I think the balls would fall a bit easier on the table in your picture.
View attachment 920066
A laundry basket would have been better.Exactly. The seller is 100% a banger. No one else would put the tape measure like that. This could be a table that was purchased for a home 20 years ago, and sat almost unplayed with laundry on it most of the time. I've never seen a GC4 casting look that good in bronze. There was a later finish that was more silver color that didn't pit like the bronze one did.