IIRC Runway caravans were withdrawn from use in RAFG in the 60s. However, shortly after Bill Langworthy (RIP) and 'ShadowSheen demonstrated why the Jaguar didn't actually need wheels (rear end strakes and/or recce pods work quite well), they were rapidly reinstated. I was CFI at TRGC Laarbruch at the time and my Glider launch point control truck (Vintage 1950s?) was commandeered as a RWC caravan until 'they' found a suitable vehicle. We did all right in the end as we got an electrical rewire throughout. Bolt, horses, doors after, closing?
As an aside Laarbruch also had a hardened sunken cupola at each end of the runway with a blister just above ground. It was seldom used other than on exercises. As DI staff it was always a good wheeze to check out who was hiding there and accept their bribes of cups of tea.