Missing Sea Vixen crew ladder

Hi
We seem to have a Missing Sea Vixen crew ladder from our aircraft (XJ494) of the Phoenix Aviation Museum at Bruntingthorpe. There may be a very simple and inocent answer as to its whereabouts, in which case we are sorry to waist everyones time, BUT, If anyone has been offered one or knows where it might have disappired to, we would be very greatfull to see it returned. It was painted yellow the last time we saw it.
Thanks in advance,