Welcome to Lumber Jocks, Filip. MC, the piece you inquired about is a (forgive my spelling) chevalet du marquetterie and is used for fine cutting of veneers in the process of marquetry. By the way, Filip, very nice piece in the fourth picture. That cat looks almost alive!
Hello ,the homemade tool is a chevalet de marquetry ,the other tool is an italian jigsaw.Go see my first project and a lot will be come clair i think.You can always put a comment there .I will replay as good as i can.