I have gotten to look down the tube of a number of 70's/60's era scopes.
The midpriced scopes today are clearer than the midpriced scopes of yore.
I am using a couple of Redfield 3200 scopes in small bore prone. These are scopes from the 60's. Everything is clear to the edges and these are fine scopes. These were expensive scopes in their day, and still are over priced on the used market!
I have a couple of Unertl spotting scopes, the 65mm ones with 45 degree offset. The new one I paid $800.00 in 1999. I cannot tell any difference in clarity between it and this $100 Celestron 65mm scope. Maybe a teenager will see something.