In 1977 I bought a set (4) of 19" Denmans for my 1930 Townsedan, all wrapped up in brown paper. At the same time I also bought a set (4) of 21" Denmans for my 1928 Phaeton. I liked the look of their 4" white sidewalls.
I stuck both sets in a cool corner of my garage. So, now 38 years have passed .... and they are still in their brown paper wrappers, in a cool corner of my garage. As has been posted, these tires are indeed top-of-the-line tires, and after all these years still look as pristine as when they were shipped to me - no cracks or other defects noted.
I guess we all have those 'I'm going to get around to it one of these days' streaks built into our DNA. I have since decided if my 19" Firestones and 21" BF Goodrich tires ever wear out, to replace them with the new original tread-design Goodyear Diamond Tread.
I can't post it here, but when ever 'I get around to it', I will post them on both the Ford Barn 'Swap Meet' and the MAFCA Classifieds.