n/s rear negative camber

I noticed uneven wear on the inside of the left rear tyre of my 56 Tourer so I had the alignment checked using the Hunter system. The result was -2.36 degrees camber and it couldn't be adjusted any further. The camber on the other three wheels was within spec. I was told it would have to go back in for investigation. Any suggestions on what the problem might be please?

Seems to be common on the tourer Mine is bad but not as bad
The cause seems to be general wear on the bushes over time and lack of adjustability.
The solution is either renew the bushes (expensive) Or I have heard a 97+ Prelude SPC adjustable ball joint can be fitted to the existing arm which requires pressing the old one out.
Part # 19 and 20 in this diagram
https:///honda_car_parts_selection_pfk?block_01=17SED601&block_02=B__2900&block_03=697&block_05=hcr

The replacement part is
https://www.ebay.com/itm/SPC-FRONT-BALLJOINT-CAMBER-KIT-97-01-HONDA-PRELUDE-SH/253483292217?fits=Model%3APrelude&epid=112730085&hash=item3b04c81639:g:zQIAAOxynapRiSoG&vxp=mtr

Both are expensive solutions and you will probably have to budget for new bottom camber bolts and the time required to cut them out.
Mine are seized and I have new ones but no time just yet.

Thanks for your reply.