Good luck getting one from India. I've already tried for a few years and zero bites. Tried "India-Mart" and nothing. I buy and sell parts, here and there, and this is some of the feedback received from various folks in India on this topic.

... "They stopped that facility in 2003 or 2004. During the 80s, it was very common to see cars getting dieselized for better economy. Diesel is subsidized in India. Most common engine swaps were done with Indian OM616 made by then Bajaj Tempo [Now, Force Motors] & Izuzu engines. The classic Morris oxford aka Hindusthan Ambassador was the common target. Most of them got dieselized during this era. But, nowadays, the economy has grown. Its a use & throw culture prevailing here with automobiles. No one is bothered of these kind of mod jobs. Again, Force Gurkha is a very very rare vehicle on Indian roads. The reason being, most of the people, i would say 99.99% prefer the Mahindra Thar [Simple, rugged Indian avatar of the original Jeep Wrangler] over Force Gurkha. ... Even if you can manage a new engine from the dealer, you would need a consent letter from the RTO [Road transport Officer] to grab it. ... "

So, the hurdles I see are 1. Not sure there are many viable donors out there, 2. Even if you found an engine, "who" will act as your agent to move it from point A to B, 3. What happens if you get a clump of metal? 4. What price point is a deal?

Good luck on your search. CoPart started buying and selling cars in India but not sure the infrastructure is up and running to get cars shipped yet.