I looked into this some time ago.
I have soft dash LSE with extra wood around various switches, etc . It has same as later Disco 1/with airbag.
I wanted a wood steering wheel. Looked at P38, various Jag ones and all have different/larger splines.
IF you made an adaptor, it would void any insurance, unless it came from someone who had it tested and approved.
Only way I could see was change steering column; yes, too hard.