Can we modify a Crawford chuck to take 5C Hardinge collets?

Modifying a Crawford Truegrip collet chuck to take Hardinge fine thread 20TPI collets
The point of this modification is to use the Hardinge 5C collets that are more popular and still available on a Crawford Truegrip collet chuck that has the same features but a different coarse thread.
The Hardinge 5C collets have 20TPI right hand thread and the Crawford has a 12TPI left hand thread. For obvious reasons the Crawford coarse left hand thread is the more desired thread, but the lack of collets makes it not so.
With the left hand thread we are closing the collet turning the chuck key to the right, the same way we close our three jaw chuck for example. The coarse thread is also faster to close, meaning less turns with the chuck key to open or close the collet.
Unfortunately collets for these chucks are so rare that you might not have ever seen one live, let alone to have one. Or maybe you don but you are holding on to them...
Link for 20TPI thread plate
www.ebay.co.uk...