When I started smoking this was the first blend that really turned me onto piping. I too searched for a replacement and along the way ended up finding other English blends I just liked better, instead of finding a match which I never really did.
In my craze for finding the exact same thing I noticed the description on TR for 536 was similar to two Peter Stokkebye blends,
English Luxury and
English Oriental Supreme. I purchased EOS to see if it was the same, here it is side by side with 536. The 536 has some years on it, 2020, probably older.
Its been awhile since I smoked them side by side so I'm a little fuzzy on if the EOS was close or not (Ill do this tonight and report back). The tin note has some similarities, not spot on though. The other thing I discovered while trying to find a match for this blend was if it had orientals or not. Some reviewers say it DOES while the description itself doesnt list any as an ingredient. To me the blend has a sourness at times that I associate with Orientals but I'm only 4 years into smoking and unsure how good I actually am I picking out individual leaf in the smoke.
This brings me to the other PS blend that had the same description which is English Luxury, which doesnt have any orientals. This could be the match potentially but I have not purchased any to see. So maybe you could pick up both the PS blends and see for yourself.
I'd start with English Luxury and Oriental Supreme and go from there.
Not sure if Peter Stokkebye actually blended for Nat Sherman at some point I just think its very strange that the descrption on TR for 536 is the same as English Lux/EOS. Here they are: