The T01 was less pretty than the 50 it replaced. It was meant to be as powerful as the 45, but wasn't. It did nothing better than the 45; it wasn't even as accurate.
If I was still a collector then I consider the T01 as a must have rifle because they are rare. Far rarer than the older 50's. They were going for a song at one time.

I fancied one at the time but it soon became apparent that it wasn't a match to the 45. Anyhow Theoben were on the scene if you weren't going HW.

As for the Webley Omega it was too late and they didn't address the trigger. I bought an Eclipse having bent a few Theopben's barrels. Didn't keep it long purely due to the time it took to load and an indifferent trigger. Bought a Fenman for my father and still use it. Have a Theoben SLR88 too; keepers. A tuned Omega because they point so well.
Most of my collection has gone as most were best kept well within farmyard range. However, I did keep the 45 over a HW35E. Will always have a FWB Sport or two.

1980 were the days of the HW35 E, Original 45, FWB Sport and the increasingly rare to find mint Webley Vulcan; a BSA Airsporter or Mercury S if you must, or if exotic a BSF. Fun, then anything from Sussex Armoury. (Anyone have an AR7 for sale?)