I have full set of 16in tele dials from my old 156 SW with two all-season tyres fitted on the fronts. Last winter they were superb on the 156. They fit and look fine on the GT but haven't tried them in snow yet.
Using them on the 156 was absolutely brilliant. I have a colleague with a 4WD Subaru and I could get everywhere he did with no problem whatsoever. The previous year, with ContiSport 3s on all round, I really struggled. Chalk and Cheese.
The tyres I have are Kleber (made by Michelin, apparently) Quadraxers. I highly recommend them for the following reasons: They are an all-season tyre and so grip in normal conditions is very good, especially the wet. They are not too noisy either, which all-out winter tyres can be. They seem to be wearing very well. i.e. no signs of wear yet - although I only covered around 3,000 miles in them last year.
Now, before people start shouting "all-seasons are crap in deep snow and ice!" the Quadraxers are unusual in that although they are classed as "all season" they carry the 3-peak snow symbol which means they meet the standards for use in deep snow and ice. Believe me, they are absolutely brilliant in snow, slush and ice. I never even had a wheel-spin.
I would have considered using them all year round but since I'm lucky enough to have a spare set of alloys lying around and somewhere to store them, I may as well have two sets. Less wear on the summer tyres too!
I used to be a cinic when it came to winter tyres and whether we really need them in Britain. I was wrong. Believe me; speak to anyone who has tried them during the recent winters and I bet none of them would consider going back to summer tyres in the snow.
Oh, I paid around £80 each for 205/55/R16 size from ATS. Fully fitted.