Here’s what I found.
SOLD FOR £1,001
Four of these guns were made, two hero light up versions and two static versions.
This is one of the static versions, although the power pack is removable.
(this is made out of an old jack plug with a female connector ........ typical high tech stuff from the BBC).
Gun is made of resin + fibreglass.
The previous owner had the gun autographed by Peter Davison.
The gun was also used by David Tennant for a sequence on Channel 4’s Friday Night Project that aired in 2007.
I also found some further eBay listings relating to other Doctors