Leather back.... I am not sure if it's a zelcova or as you suggested possibly a Ulmus Parviflora.
At a festival, at a workshop, I got such a tree for free. It was labeled 'Zelkova Parviflora'. When I asked the owner of the shop that organized the workshop why it was labeled like that, as Zelkova Parviflora does not exist, he explained that elms are often called Zelkova due to import regulations - elms are prone to diseases that Zelkova's are not, so that's why they were renamed Zelkova. Zelkova's were easier to import and the difference is not so easy to see for most people.
Not sure if that's still a thing though, elms are abundant so importing them does not seem such a big issue.