I was confused when you mentioned a red wax seal. From what I know of the 1935 Sandeman, the was applied at Sandeman for that Jubilee bottling, was always purple. I wonder if it may have been bottled elsewhere or they ran out of the purple during bottling and changed over to red. Very odd.
I owned 2 cases of this Vintage Port and have now consumed 12 bottles over the last 8 years, actually 11 ... as I gifted one. Part of the agreement for being able to buy these in OWC and their straw handsewn sheathes, was that I would sell the 2nd case. My wife made sure that happened.
This is a delicious Vintage Port, fully mature and on a wonderful plateau. Make sure your bottle goes to someone who would appreciate it.
I assume you are in the UK and if so, you should do your best to try to offer it to one of the many Port lovers here, who would appreciate your bottle.