I think it would be fun to do some tests of how well some of the tapes (pre70's) would do in a modern machine. I'm sure you're probably finding this tape for a song but like I said, this is voice grade tape and just about any other Ampex, 3M, BASF , Agfa, Audiotape etc. would be better for the demands of music recording. One of the problems that I think you'll encounter with using these older tapes is tape saturation. This is just my best guess, but I wouldn't think that they have very much headroom. I'm sure that this varies a great deal from tape to tape (type) but the amount of hiss that you find on old master recording and prerecorded r2r tapes seems to indicate that pretty conservative input levels were employed to avoid any saturation distortion. Of course, as the subscribers to the Tape Project can all attest, there is nothing wrong with the music that's contained on this old oxide.
As far as physical problems you might encounter with old tape, particularly if it wasn't stored carefully, would be loss of lubricant (drying out), warping/curling, and excessive oxide shed.
LOL (loss of lubricant) is sometimes also called vinegar syndrome but personally, I think they're related rather than the same. Just like sticky shed, it is a change in the chemical make-up of the tape. It's easy to spot. When you first open a box or bag the smell of vinegar is evident. Many times, if it's stored in a cardboard box, when you remove the reel you'll see an image of it on the inside in a light brown discoloration. Actually, this discoloration is a good thing since it's evidence that the cardboard has absorbed the acidic acid that's been released from the chemicals in the tape (high school science will tell you that acidic acid is what vinegar is). If left unchecked, the loss of binder chemicals and the acid will totally release the oxide from the backing. I've seen pictures of sections of tape that all you can see is the clear backing in the tape path and piles of oxide slivers before the machine could be stopped. This is a very extreme case that's good for scaring restoration guys into being more careful during a first pass with an unknown tape but in reality, doesn't happen very often. What does happen is oxide shed of one level of another. In practical terms, oxide shed is more of a pain than anything else. You have to constantly clean the tape path and that's no fun.
Warping or curling is usually associated with an improper tape wind but this isn't always the case. With an NOS tape, storage is key. The tape winds are constantly trying to move to the center of the reel. Anyone whose wrapped a piece of dental floss around a finger can attest to the fact that even if you apply constant tension to the wraps, the tension at your finger increases with each one. Most of us throw away this floss in plenty of time before our finger tip turns black and falls off, but what do you think would happen if we put it on a shelf for say,.. 3 or 4 decades? For the most part, there isn't enough tension on the tape wraps to case any shifting of the tape but changes in temp. and humidity allows the tape to go into motion. What you end up with are sections of the tape wrap that are loose (allowing tape "pops" ) and others that are very tight. This motion of a stored tape is never linear so sections will stick out of one side or the other allowing curling to tape place. Even the looser winds have some tension and they still want to move to the center of the reel. This results in the outer edge or edges (if it's just a loose winding) to curl toward the hub. Any curling or warp will reduce the tape to head contact and result in a significant loss of signal.
How I do go on! Holy cow, I certainly don't mean to scare folks but once I get on a subject,.. well, I guess the evidence is clear to see!
In any case, set your machine to record with the lowest setting available and be conservative with your recording levels. You'll need to experiment a bit but you can conceivably record on any tape. Personally, after hearing a very early recording a few weeks ago, I'd love to find some 3M 111 to fool around with (Richard Link's Doc Evans tape was recorded on it as heard at Larry Toy's get together).
Regarding CrO2 and metal tapes, I'm not sure of the dates that those were used but it was for use with the slow speeds that are encountered with cassettes. Memorex developed them and I had a few friends who worked there. I never used their products again! (just joking)
Ben, the tapes that were sold under several names; Shamrock, Concertape, and RadioShack , just to name a few, were B stock from any of the major players at the time (mostly Ampex and 3M). The reason they never include quality info is they never knew what was going to be loaded onto those reels when they printed the boxes.