What’s an acceptable grade for vintage cards?

[nolemmings]

My targets:

1970-77 MT (although nm-mt acceptable for 1971 Topps)
1960-69 NM-MT
1950-59 NM
1930-49 EX-MT
1920-29 EX
1910-19 VG-EX (although I usually seek higher--this is the floor grade)
pre 1910 VG

obviously this is just a guideline--eye appeal comes first. Also, there are issues pre-1950 and some test and regional issues thereafter that require a more flexible approach, as they are not as frequently found. Pretty much anything post-1950 topps/bowman is so readily available I don't usually deviate unless I see a card I believe to be noticeably undergraded (again, eye appeal).

EDITED TO ADD: I should say that I have so soured on graded post-war cards that I now often buy raw. In those instances, I realize that some of the 1970's cards I buy are probably unlikely to merit a "9", but I have no intention of submitting them and even less intention of paying grossly inflated prices for some flip when millions of a particular card are out there and a beautiful copy can be had far cheaper.