Parts are easily available. Go for Engine rebuilt. BTW in which city you are located?
Nowadays most illiterate mechanics are Lazy but google/mobile/keyboard/ YouTube warriors , these Kaam chor have never learnt something from their sincere Ustaad G and now rely on YouTube videos so they will suggest you to swap for easy way.
Kon itni mehnat karey, Bore ka cylinder ka size likha, khyal karey.. Chaddo G, phenko, new Maal Laao Lagao, saada bhee kaam jaldi mukhay.