That's quite ironic considering they were based on the rules contained in 'Charge!' by Brig. Peter Young & Lt.Col James Lawford, first published in 1970 iirc. PDE chose them for their antiquity and amateur-like attitude to gaming as he thought it would gel well with the 'style' of VBCW.
They were actually based on a set by Charles Grant and were written, VERY quickly, for the first GWP big game a few years ago.
Things have moved on a lot since then and I am close to completion of a set of interwar rules which will be published by Osprey some time next year.
We have been completing the last play tests shown on here.
http://pdesplace.blogspot.com/Regards,
Paul - PDE