Take it to your next event and see if the sutlers have an Indian made one or you can contact pedersoli. Years ago they offered a really nice spring steel one but it was about the same price as an original.
I use an original bayonet with my repro US 1842 all the time. While they can be lost it is not particularly easy to do so if you tether the socket of the bayonet to the scabbard with a leather thong. The made in India reproduction bayonets are of such inferior quality as to be virtually useless for anything you might use a bayonet for except stacking arms. To have an original bayonet that fits your reproduction US 1861 and not use it in favor of a crappy reproduction for fear of losing it seems like you're solving the wrong problem.
A few weeks ago we did some stabbing with bayonets against the side of a pig. It was strapped to a tree. (so the tip would enter the wood)
Some of the others used cheap replica bayonets and they ended up bending their bayonets when they had to pull it from the tree. Basically the metal gave way, not the wood.
One even had an damaged edge...
Ha! Gives new meaning to the term "pig sticker" (a colloquialism for the bayonet). Nobody with access to a decent original bayonet should consider using the India made reproduction in the field. If you don't have access to an original and that's the best you can do, then you just make do with what you have. Bottom line is that the reproduction bayonet is all for "show" and not for "go."
I bent a repop once trying to use the musket as a tent pole. I still use that bayonet sometimes for the remarks it gets. When I more recently fitted a repop to my 1861, I tried 18 bayonets before finding a fit.