I agree with Jim, leave as is and just stabilize any active rust. The lance head appears to have been cleaned with some type of acid, probably very corroded previously by the appearance of the pitting. Cleaning further will alter or make the markings indecipherable.
Actually lances are not that common and finding the metal parts are difficult, partly due to their length and the ability to post them. Rarely do you find a matching butt for a lance head. India recycled metal and lance parts were no exception.
A proper length ash pole would really make a good lance. White buff leather can be sourced for the strapping. This leather can be sourced from the UK, a cut belt piece should do it.
https://www.identityleathercraft.com...lt-blanks.html
Best to contact the Identity Store for white buff leather they have pieces large and small and belt length