I had to Google this.
See
http://www.bordercountiesvintageclub.co.uk/page.asp?p=8
They ran an event at Speech House until 2003.
The Border Counties Vintage Club run an annual event in Monmouth, they have had road steam in recent years but not much by what few accounts I can trace. If you look under 'Steam' on their site then there are two small pics of indeterminate age under 1975 -2008 and a note "This page is being updated"... I'll try to remember to email them before next year's show.
We don't run a car, Monmouth is too far to cycle from here, and I don't greatly fancy hiring a car for what could only ever be a sprinkling of engines. The Abergavenny rally is a shadow of its former self so there's a real opening in this area although the Speech House site is not big enough for, say, a rally even the size of Much Marcle.
It's maybe difficult to understand unless you know this area but Monmouth and the FoD may be neighbours but they might as well be on the opposite sides of the world as far as most people round here are concerned. I say this having lived in both!