I think the simple answer Jim is that they vary.
Many of those kits have turned up in different guises from other
manufacturers so I don't know whether Minicraft have bought tooling or
if the company simply likes changing it's name (!) but I suspect it is
the former.
I have built the MG TC, which was also marketed as Gakken, and it was not too bad at all.
Their SS Mercedes was very good with nice fit but the 300SL Gullwing
was a nightmare, particlarly fitting the body to the chassis.
Don't know about the Silver Ghost as I haven't seen it but it looks as
if it would lend itself nicely to a bit of upgrading with real wood and
a proper canvas folding hood etc.
I say go for it - and don't forget to let us know how you get on will you?
Cheers
Martin
http://www.freewebs.com/martsmodels/