Good question. We see the Isofrane also with the 980.023 and I believe it was a standard unchanged strap.
No idea on the other one but I know someone who has recently bought a full set so will see if he has any insight. 馃憤
Steve
ps ah it was you I was thinking of. 馃槜 Did you manage to get the set?
The Isofrane I鈥檓 confident would have been branded Isofrane and not Heuer.
For the other one I鈥檝e heard Bonetto Cinturini straps were original, but also heard they are simply similar. They were around at the time and some of the models certainly are of the same style.
Here's a good thread-
https://forum.tz-uk.com/showthread.php?211631-New-in-Heuer-Super-Pro-(now-with-pics-And-poll)
in which it is stated as Isofrane model 52018 and a Bonetto Cinturini, as Gammba says. I can't be 100% on the correctness sure but it's a good starting point.....
