Hello, 
I have purchased two nearly full runs of vintage lasts.  One for men and another for women. I got a steal of a deal.  What I would like to do is modify them to make soft soled shoes with a wide natural toe and no heel.  They are made to accept what I think is 1/2" to 1" heel but I want to modify them to be flat and also modify the toe to a more natural shape,wider at the toe and ball. I thought I would just fill in the heel with cork and add width but fear that the shoe would become too high at the ankle. Maybe if I just grind off the front sole a bit to match the heel, understanding that I will not be using toe puffs and want a soft foot conforming shoe so the loss of height may not be an issue.  I hesitate to ruin the lasts as full runs are soooo expensive. I would be willing to trade these lasts for flat lasts if anyone is interested .  Also these are wood lasts and I wonder what I should use to alter them with that I can remove later?  I have no experience in modifying lasts at all.  Any thoughts?