REME museum in Arbourfield. They are holding their annual scale model show from 11am and entry also gets you into the museum. I believe all the stalls and displays are in amongst the tanks; they were for the re-enactment days anyway.
This is one of the last events they are holding at the current location as the Arbourfield garrison is now closed and the museum has to move soon. At the end of April they are shutting the museum doors for the last time and starting the relocation to RAF Lyneham in Wiltshire.