Actually not a one off prototype but an ex Modellers World (???) kit that Geoff bought in. Ken Mason's report of the build convinced Geoff that the kit wasn't good enough to be in the Gladiator range so it hasn't been offered for sale. I had a set of etches printed for both the C1 and C2 with the intention of building myself and seeing what needed to be redrawn and what might be used from the LBSCR H1/H2 kits. The etches are still aging away in the workshop! Happy to supply as an aid to scratchbuilding if anyone wants a challenge.
David