Well, I took action ...researched as best I could and made a decision. I will be going with 3 each (with new wheels) ST225/75R15 E rating Carlisle brand. I have no illusions and will keep you all posted as time rolls on.
Insofar as the outside plumbing/cleanouts ...I am still researching that problem.
I did read that it is possible to get that cleanout area protected in some manner -- protection from the Driver Side blowouts, I guess.
So, again, any advice is welcome.
Ron