Custom made by KAFFEMASCHINE MOTORCYCLES in 2016 for my personal bike (https://www.kaffee-maschine.net/)
Made of premium leather tank bag for cafe racer. Approx 14in (L) x 10in 
x 4in (H) expandable to 8in. Anti-skid pad underneath. 2 large leather belts. Leather pads protect the paint from the chrome buckles. (never had any scratch on my tank with it)
2 compartments with cloth liner absolutely clean and not stained. 1 compartment for road map and documents. Perfect for any European cafe racer.
$750 plus shipping
The Egli-Vincent 
Looks very similar to my two Elegantboy tank bags, one of which has been on my ‘72 V7Sport since the day the original owner took possession of it from the dealer. Great bags.
This company is indeed doing a lot of Moto Guzzi Cafe Racers and the bag that you mentioned may have served as a template to make mine.