Larry - if they are 70's A's they will have an ink stamp (Zildjian) on the bottom. If they are 'hollow-logo ink stamps' (just the outline of the letters) then you really lucked out with a fine set of cymbals. More photos when you get em!As for cleaning, it's all personal taste, but I wouldn't touch those. Play em as they are. And yes, you're -very lucky- to still have your old man around. John
I'd say it a little differently...
If they are "1970s" cymbals then they may still have a hollow logo Zildjian ink stamp on the bottom. Or they may not if it has been cleaned off. It is more a case of if it has a hollow Zildjian ink logo we refer to the cymbal as "1970s". The actual years for the hollow ink Zildjian on the bottom are still unclear.
And just to make more trouble, there are also hollow Zildjian ink stamps on the bottoms of some cymbals with what we call "1960s" stamps as well.
All of these things are illustrated on my site. First the Hollow Ink Zildjian logo (why use 1,000 words when one picture does it nicely?):
[img]http://black.net.nz/cym2013/70sA3.jpg[/img]
and corresponding entry:
http://black.net.nz/avedis/avedis-gallery.html#HollowInkZ
Then read from the 1960s entry onwards:
http://black.net.nz/avedis/avedis-gallery.html#60s
If you can't identify the pressed in die stamp from these entries then you might need to look earlier or later. It's all there for the reading.