To my knowledge these are not yet available through normal supply
channels.

I have a quick question - would you be adverse to drilling a couple of
holes in a hardback seatback to install hardware for a tailsock?
Complete, thorough and painless instructions would be available, and
the correct drill bit would be supplied with the hardware.

I just want to get a feeling for this technique (the most secure) for
attaching a tailsock.

Thanks,

Peter