To show how experts disagree on restoration, I am offering two quotes.
The first is from the excellent book on Violano restoration by
Mike Kitner and Art Reblitz:

  "D and G strings: "Super Sensitive" brand, medium tone steel core wound
strings (and other brands of similar strings) can be tuned properly.
Most gut core strings will not work on the Violano, as the tension
required to tune them is much lower than the weight range of the tuning
weights."

The next is from a Musical Box Society Publication article by Edward
F. Hattrup:

  "The "D" and "G" are an altogether different problem; these must both
be wound strings on GUT - never on steel."  ...  "If steel-core strings
were to be used for "D" and "G" too much weight would be required to tune
them.  This could warp the bridge and put unnecessary strain on the rest
of the violin.  Remember, these violins are over 50 years old, and repair
or replacement is costly.

Ed Kigler

 [ I get the impression that these authors experienced very different
 [ fiddles.  Did Mills, indeed, produce instruments with gut and gut-core
 [ strings?  If so, then they certainly altered the tuning weights (and
 [ possibly the bow wheels and rosin).  -- Robbie