Buildings of that era had no foundations, true?

Does underpinning cure, or postpone, a problem?

Personally, I wouldn't worry about underpinning, provided it was done by a
reputable company with guarantees. This is provided the reason for it is
known. For example, upgrading missing foundations is a good reason. It
slipping halfway into a mine shaft is a bad reason.

However, I would definitely ensure that there would be no problems with
insurance if I purchased it, and would want a lower valuation to cover my
problems selling the property on as some people are rabidly against any
underpinning. I would certainly get a full structural survey.

Christian.