New Moto Guzzi Door Mats Available Now
Since you are making a custom bike why not get a Thruxton seat & cowl and have the front remolded to fit whatever tank you are using on your project?
Another option for you if it works.( It has worked for me many times in the past but I live within 150 miles from Corbin's). You can have Corbin build you a gunfighter+ lady seat off your stock T3 Base. It will fit the bike and keep the metal Guzzi base that bolts up to the frame. Only possible issue could be that you wont get to test it for comfort/ butt fit and look as in the walk-in Corbin custom jobs jobs the do when you are there in person. As per the " round"? LM seat which one are you referring to? AFAIK both the Gaman seats are currently not available as Stucchi who re-popped them went belly up and was restructured so nothing available currently. The other seat for the LM1, a hump type cafe seat was produced by Giuliari and Curtis @ Harpers may be able to help you with that