Had tires put on the front of a MH I had , when I was walking out the tire guy said "we checked and put the rears at 65 and the spare to 65 too" I said thanks and went on my way.
The following morning when I went to the MH to check on things I noticed the rear tire cover bulged up ??? Removed the cover and the tire looked just like your first picture. I for some reason checked the pressure on it . 90lbs of air pressure ?? max was 80... I checked the other 6 tires NOT one tire had the same amount fronts were in the mid to high 60s and the rears were in the 70s . Being parked were the sun had not been heating the tires up...
I drove back to the tire shop , called out the manager and asked him to check the tire pressure on all 7 tires. After he looked at the date code on the spare being 5 years plus a few months his comment was it aged out.
After a little discussion I had a new spare put on and all the tires were set at a set pressure ! 60 frt and 65 Rs... The manager stepped up and took care of the situation...