Somebody must have replied to this thread today, then deleted it, as I got a notification in my email inbox about it, but I don't see any reply.
However, in reading Russ' last post again today, I see that I did not reply to him. We were kind of waiting for Jan to clarify this, but he was busy with Chelsea in the Olympic Trials around the date that Russ posted this.
Russ wrote: So there are a couple of possibilities.
1) Kirk's black pole which had a 550+ label on it that Jan used in Munich could have just been a regular black Cata-Pole with a 550+ label on it (and the label could simply be a mistake).
2) Kirk's black pole which had a 550+ label on it that Jan used in Munich could have been an S-Glass pole with black pigment rather than green. If that's the case, then, as I said, I never suspected or knew that Cata-Pole ever made any S-Glass 550+'s that were black instead of green.
Russ, I don't know for certain, but I believe that the answer to your quandry is (2).
If it was (1), then I'm sure George Moore would have told me about the mislabeling. I had a series of Catapoles 550+'s - not just one. It would be very odd if every one of them was mislabeled. Remember that these were "early models" that I got in May 1971.
It was 1971 when George gave me most of the poles, but he might have sent me my heaviest one in 1972. I can't explain why the heaviest one (that I got later) wasn't green. In fact, I really don't recall exactly when I got that one - it could have been June 1971 - I just don't remember.
Honestly, I didn't know the difference between E-Glass and S-Glass. All I knew was that these were the latest models that he had, and he wanted elite vaulters to test them for him. I'm sure he also wanted the free advertising that he would get if any pics made the news. For the pole of mine in the pic above, that certainly turned out to be the case, as that photo went world-wide in an Olympic highlights book!
There would have been absolutely no advantage to him giving me old poles - E-Glass poles as you call them. So if your classification of E-Glass and S-Glass poles is correct (and I assume it is), then they had to be S-Glass poles.
The other possibility that you didn't consider was whether my poles were black or green. You can't tell the difference in a B&W photo, but I assure you that all my poles were black. Also, if they were green, then they would not have allowed them in the Olympic Final.
This brings up an interesting situation ...
Jan was able to jump on my black S-Glass poles, yet other vaulters were not able to jump on the green S-Glass poles. So the PV officials differentiated which poles were legal and which were illegal purely on the basis of color!
This is an interesting revelation, as I've just come to this realization now ... 36 years later!
Jan won't have to return his medal tho. The issue was that the "Catapole" brand - with black poles - was available well in advance of the Olympics (1971), but the green ones weren't available to all athletes world-wide until 1972, so it was deemed that the Americans had an unfair advantage.
Funny, eh? A green pole made of S-Glass is an unfair advantage over a black pole made of S-Glass! Ha! ha!

As you said on page 162 of the book you co-authored with Jan - "Illustrated History of the Pole Vault" ...
Seagren, Johnson, Smith, and Isaksson, however, had to scramble to borrow poles and make last minute adjustements in order to compete. Under these extremely difficult circumstances, it is nearly a miracle that Seagren managed to vault 17-8 1/2 (5.40 m) to win the Silver Medal, and that Johnson won the Bronze Medal at 17-6 1/2 (5.35 m), using a short run and a pole borrowed from Decathlete, Bruce Jenner. Neither Kjell Isaksson nore Steve Smith was so lucky. Both the Swedish star and the American failed even to qualify for the finals, on brown Sky Poles.
Russ, as we discussed by email, we think that Jan used Bruce Jenner's poles in the Qualifying Round, and mine in the Finals. You'll have to update that page in your next edition!

Kirk
p.s. Jan, I'm still waiting for you to reply to my email, where I asked if I could borrow your Bronze Medal - since you borrowed my poles.

p.p.s. Russ, I found the original thread where you first started some research, and talked about writing the book! Here:
http://www.polevaultpower.com/forum/viewtopic.php?t=384&highlight=evolution