Remove the Paint, they were blued, like Husk's example in post No19, (nice example) I've had a few in this condition in the past, I had an outstanding example many years ago, looked like it had just come off the production line.
Anything painted by the Indian Army needs to be removed and done in Suncorite or similar, I'm sure the Indians used the good stuff for there own use first, metal work around the house or push bikes etc and replaced it with a few gallon of thinned out cheap black gloss.