Interesting that you are using the Proxxon saw - I thought until now, that it would be too strong, so make such cuts with my saw-knife (I do not know, how is the correct term (either in english and also german 
)
according sellers it is called
Handsäge mit Griff / Handy Craft Saw II
www.traudlsmodellbau.com


according sellers it is called
Handsäge mit Griff / Handy Craft Saw II

Tamiya - Handsäge mit Griff / Handy Craft Saw II
Fachgeschäft für Plastikmodellbau und -zubehör in München