Agreed, that the blade could be older than I originally thought, but the 'extreme' etch gives the impression that the patterning is 'raised'.
After, re-viewing the pictures I have made various observations, I am not saying that my deductions are correct but feel they should be mentioned so that they can be discussed in a 'learning environment'.
I do think that blade and hilt may have been 'mated' more recently than the 19th C .
When two layers of steel are placed together, rust seems to develop more readily ( I think it is due to an electrolytic action and the 'trapping' of dirt and moisture). This is shown on the picture of the hilt below, where the 'cross piece' meets the guard) However there is no real corrosion where the blade and 're-inforcing' plate meet. The edges of the decorative area of the 'plate' seems to be very crisp.
The rivet is not peened over very neatly, the deeper 'depressions' would harbour rust...but they seem clean. The rivet has slight gaps between 'it' and the plate ...still there is very little corrosion or dirt, which would collect there. Also part of the rivet's edge is slightly 'burred' over, as this 'part' of the rivet would be thin and 'exposed' you would expect it to have corroded away(if done 100 years or so ago)
The 'patina' on the blade (surrounding the re-inforcing plate) is almost uniformly the same colour and is translucent....you can see the 'patterning' through it. Old patina would be created by corrosion which would not be uniformly translucent. It looks as if the blade was overly etched, somehow 'knocked back' (with a salt and vinegar solution
) mounted onto the Khanda hilt and then cleaned. I also think the hilt was cleaned prior to the re-mount ...as the edges of the re-inforcing plate are very clean yet the blade next to it is not.
The eyelash markings and the dots seem to be made by a small triangular stamp and a round one, as opposed to a 'complete' eyelash stamp...as neither are perfect copies of the other. Whether this is relavent to 'age', I do not know
Regards David