As Alex has well noted, these appear quite genuine, although tulwars seem to multiply in and around Rajasthan, as the supply seems boundless. If these had come from the Bikaner armoury they would have had stippled (dotted) script markings at the upper part of the blade. Naturally not every weapon had to have had these as there must have been tremendous volume of stores there.
With these markings, I agree that the one with crude arcs and dentated lines probably was attempting to imitate the so called 'sickle' marks, as these seem to have been prolific on examples of the paluoar 's of Afghan regions to the north.
Also the 'arrow' mark was used by one of the Rajput clans, but I need to find it in my notes. I believe the symbol was illustrated in Tod's book on Rajasthan.
The other marking which seems geometric resembles markings used by the Kalash people of Chitral, an ethnic group formerly Kafirs of Luristan who are animist and use these kinds of symbols.
It is difficult to say exactly what situation these tulwars came from, but often these crude imitation markings were used to imply quality (value as Alex has noted) or in more pragmatic circumstances they were applied to imbue certain symbolism of perhaps talismanic nature.
Interesting examples and thank you for sharing them here, and welcome to our forums!
