I use a similar arrangement for travelling, my brush is the Kent Silvertex but I use the same exact razor, when the handle is folded the entire razor plus four blades fits nicely in a 35mm cartridge box.
Do you know what is the model number of this Tech? , last time I attempted to identify it Mr Razor site was pointing to a 4 piece Canadian pre war job but mine is made in England.
I'm not sure, but my best guess is that the razor used to be part of the No.26 Set (this one) from 1946. Mr Razor also lists a British 4-piece Tech from the 1940s (this one), but the knurling on the handle parts is obviously different. These two and the Canadian one with yet another different knurling style (here) are the only examples of this razor I know of.
Hadn't thought of the 35mm cartridge box option, that's a great idea!