I don't think the blade edge is well supported with washers and you really need the base plate cut back to make it into a devette. That would destroy the 15C base plate. Alternatively you can pick up a Gillette Old or New and just cut off the combs if you wanted a try a devette.Today was my first ever Devette shave. I only did WTG and 80% of an XTG pass, then I wimped out and reattached the base plate, and finished the XTG and onto the ATG pass. I had a couple of the tiniest weepers. A pretty good shave otherwise. I'm not sure I would do this every day, but I'd be keen to explore this technique further.
You may as well use a shavette which uses half DE blades but has better support for ther DE blade. Shavettes can be found at very modest prices from the usual online suppliers.