From waht you say your flute almost certainly has a conical body with a parallel bore head. The modern Boehm flutes have cylindrical body & tapered head. This means that even if you did find something that would fit it is 110% certain that combination would never play in tune. You will need to find a maker to produce a suitable head or keep looking on that well known internet auction site for one.
I agree with contra448 that you will not be able to find a suitable replacement that will work and play in tune. In your original posting you said your headjoint has "had it". Could you elaborate - is it broken, cracked, or what? I would bet that your wood headjoint has a metal liner inside it - is that correct? Even if the wood is badly cracked, it CAN still be repaired.
Well I've settled on a baroque traverso. I decided to get a student traverso from Aulos in the meantime.
I realise (now) that my broken flute was almost baroque sounding - sweet, and subtle, with warm colour throughout, but without the delicate shading.
The Aulos plastic Stanesby is really good, but I'm failing the 3rd octave F/Fsharp. The instructions do say that is very difficult to do, but I'm surprised it's really this difficult.
When I tried a number of Rottenburgh and Kirst models, there was no problem with the 3rd octave F/Fsharp, but these were much more expensive.
Does anyone else play baroque traverso have any ways around this?
The prices of wooden headjoints are really high. I guess they are specialist equipment. I don't think it's worthwhile contaminating a new headjoint with an average old flute, so I'm going to start from scratch.