Momo steering wheel boss recommendations?

[Horacetoo]

I have a 70 Traveller and the combination of Morris Commercial front seats (at maximum rearward travel) and a 'retro'17'' banjo? wheel - both fitted by a previous owner - make getting in and out difficult - and when driving the wheel rubs on my legs.

Any recommendations for a SPECIFIC Momo boss that will work with the very long sprung centre contact for the horn please?

I bought one that's not deep enough, meaning that sprung centre, even when compressed, still sits proud of the boss face, meaning the steering wheel can't be fitted!