The problem was they were a bit short for a longbow and, furthermore, a classical splice eats some length (the splice's length itself). So I had this idea : what about a splice with an internal added part ? It should work as well as a classical splice.
The only problem I can see is a possibly smaller glueing surface. But I think it is possible to lengthen the added part, even as far as the fades. Below is
an example with a box-joint, but any splice might be conceivable as well. Overlays might be added on back and/or belly side.
What do you think ?