Cut the long story short: I have decided to experiment and give it a try myself. This is the first result after a day of cutting and grinding with angle grinder. Blades were made from CSN 14260 spring steel, 5 mm thick. The longer one is 65, and the shorter 60cm long, with 5 cm / 4,5 cm width at the widest part.
Both blades are thinning to 3 mm some 15 cm from the point, then to 2 mm just behind the point. The point is left thicker for security (5 mm). To save some weight, blades have a concave cross-section, with stong back-rib (5 mm) thinning to 2 mm in the thinnest part close to the centre. Both blades are made blunt, of course:)
I still need to finalise the shape and clean them, then I will send them to a professional company for hardening and tempering. Will keep you posted about the progress :)
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