Are you referring to the V shaped mainspring?
Most likely a spring from two other Colt models, the Official Police or the Officer's Model would interchange with no discernible difference. Keep your eye peeled for one of those which are generally available and inexpensive. Purchase it for little cash outlay and install it to see if it won't solve the problem.
I have a Python, Official Police, and Officer's Model and have observed that they APPEAR to be the same when inspecting the revolvers side-by-side with side plates removed. Many other parts interchange between these models.