Solving a sometimes problem

When we are banking goods trains up the grades on Bylong the bank loco is usually a D50 with sprung buffers and no front coupler, so the load is taken on the buffers which is to allow the D50 to slowly drop away from the goods train when it has crested the grade, very prototypical.
However we occasionally have a problem when the loco buffers slip off and past the buffers on the guards van when on a curve. This of course causes no end of grief, bringing the train to a stop.
I have had an idea on how to fix this for several years now; no need to rush into things ;-)
I should mention that when the train leaves Bylong it enters a tunnel that is about 3 metres long and the track runs on a 100mm wide road bed with a 1200mm drop to the concrete floor so it is a little bit important. We have never had anything hit the floor yet, amazing how it focuses the minds of the two drivers.
I worked out that part of the reason for the buffer was problem was that I was using a Stephen Johnson LHG and although it has reasonably large turned brass passenger car buffer heads, I realised that when on a curve the longer the van the more the van end projects away from the track centre and hence the buffers on the loco.
I decided to use a shorter guards van to reduce the overhang effect and settled on three old Trax MHG vans that I had.
I cut the buffer heads off  and replaced them with large cast brass passenger car buffers from L&C. Now I know you will say "but you can't get these anymore" and I will agree however I had enough to do the three vans which should be sufficient for any operating session.
Ian Lindsay Models also used to make some with a slightly smaller head but they aren't on his web site now.
I guess this doesn't help anyone trying to do something similar but maybe Ian Lindsay Models or Ozzy (available at Casula Hobbies) could be convinced to run them again.
Anyway are here some pictures to show what I did.

First I marked the centre of each buffer head and drilled  a hole with a no. 59 drill, I then cut off the head flush with the back and drilled a slight recess with a no. 52 drill to take the thick shank of the passenger buffer. I then glued the heads in place with super glue.
A quick test revealed that it was successful and I then did the other two vans.

The buffer heads do look a little large but as they are now painted black they are not very noticeable.
The next operating session will be the acid test.