Kutter, a 330 Weaver actually has a rather long eye relief. I have had several on older rifles.
A suitable eye relief for sure,,I've got a couple and an older (29S?) model with the wrench & screwdriver adj. on it. Any of them mounted like the one pictured and I'd have to crawl nearly up onto the rear of the bolt to see anything. Not where I'd want to be.
I think the answer is probably as someone has said that the 'booster' extends the 'scope eye relief. That's something I know nothing of, but that statement and the pictures together would make sense.
I kind of like the old 330's. They just look right on some of the early sporters. However in this case I don't think this rifle started out with a 'scope on it. If it were mine I'd remove it and it's mount and the holes would be gone. I'd also remove that aluminum butt plate & replace it w/a suitable one of steel. I just like that older iron sighted sporter look anyway and this one strikes me as one of those.