Pete Rutledge <email@example.com> referred us to Waterford's Paramount restoration services site
and within the "Block" link is this line of text:
"Many dealers continued to order the Vintage decals through 1975, when the Block style became standard."
This seems to imply that the dealers had some control over which decals came on the bikes. My '75 P-10 (which is similar to several others I've seen) has the Vintage decal set, a standard Reynolds 531 decal (not the special Schwinn or USA version that doesn't refer to butted forks/stays) up high on the seat tube where you would normally see the Schwinn Quality seal. I've seen some '75s and '74s (possibly some '73s, I can't remember) with the Block decals. Was this a dealer option? It is not on the '72 or '75 Paramount Order form and I don't have a '73 or '74 to see if it is on there.