Here is a possible source of transfers for a wide range of models FYI: http://www.classictransfers.co.uk/transfer-category/ducati/?region=international&alphabetical=d-h They also do stickers for Marzocchi, Ceriani, DellOrto, etc. I recently bought some transfers for 1980s Marzocchi forks.
I checked them out when I was getting the 907ie and Pantah repainted. They have a useful range but not quite what I needed. I ended up getting the 907 decals from Bike Graphics and the ones for the Pantah from Imageworks who supplied first class stuff.
I agree that Imageworks are really good if you want a complete set of big graphics for a model like a Pantah - I use them too. ClassicTransfers are more useful for supplying odd items for older or rare models, or bits like the yellow stickers on Marzocchi forks and shocks, for example.
I agree Pete. Classic Transfers seem to be very good for the more unusual decals that you might only need the one or two of. The more suppliers the better I think.
