Is this dry rot beyond repair?

One of those small kiddie pools would solve that problem.

 

Micro cracks are NOT a sign of "wear"......as long as they don't develop into "real" cracks.

 

Thanks for that useful piece of information, however my tyre "expert" thought them to be bad enough to point them out, and OK, he was being paid to sell me tyres, although if I remember, the price of a set of four Antares Ingens (see threads passim) (including fitting, balancing etc. etc.) was less than ½ the price of a set of Michelin Energy-Savers.

 

THIS factor is more important than you seem to think.

Those nasty cracks in the sidewalls.....or elsewhere on the tire.....are one of the oldest scams in the book.
Ranks right up there with Snake Oil Elixir.

Oh.....and most people who work at tire shops are not "tire experts".
Most don't even know the right way to tighten the lug nuts.