This bizarre machine was intended to test the efficacy of the newly-designed Otehval piston valves. Ferenç Otehval was a development draughtsman on Tešlov's team whose creativeness did not always endear him to his boss, who believed that the company's staff should spend their time on work that was of recognisable use. However, the design of piston valve that Otehval thought out (as legend has it, while being nagged by his wife) did show some promise and after much persistent lobbying by Otehval, Tešlov agreed in principle to give it a try but could not make up his mind about a suitable "guinea pig". Not one to miss a good opportunity when he saw it, Otehval took his boss's indecision as carte blanche to design a new locomotive. He had a set of drawings finished in a couple of months by dint of much overtime and burning of midnight oil and proudly presented his opus. What Tešlov thought of this exercise is not on record; suffice it to say that Otehval's name never cropped up in RSR records or minutes again.

The story of the locomotive's building by Henschel was a hoax of truly threadbare plausibility. By no stretch of the imagination would a firm of Henschel's standing have accepted an order of this magnitude without the chief engineer's signature, bearing in mind also the trouble caused by the Šahlmeti 434A in 1928. Otehval may have produced a general arrangement drawing and a few sketches, just for the sake of his presentation, but it is also hardly to be believed that a complete set of blueprints for a new design could be completed by one draughtsman in a few months without being able to marshall the effort of many of his colleagues, and how could he do that in his boss's absence or without his knowledge? Nobody's that charismatic.

As far as the 545A is concerned, this engine also never existed. After Otehval's departure from Akohniçe in 1952 however, a general arrangement drawing, which he had obviously created in secret in defiance of Tešlov's instructions, was found when his old desk was cleared out. This drawing is reproduced below: