I think you will find that most European touring bikes will be British or French. If you scour ebay.fr and various bike-specific sources (like BOBishBikesFS) you might get lucky and find an obscure French constructeur bike for less than Herse/Singer prices.
Touring generally wasn't a big part of post-war Italian cycling. I think they raced or rode city bikes for the most part. That said, there is a Ciöcc with more generous tire clearance on eBay right now. Despite the image it's for the frame, fork and headset, I believe. Still, I'd focus on French iron.
1980's CIÖCC Strade Bianche Eroica Gravel frameset - 60cm Made in Italy
