Don't think you can get the original any more. I had a look and you
can get a similar v-type linear pot from Digikey but with better
spec e.g. 1/2 Watt max power dissipation which is fine. However, the
shaft is too short, and the foot print with the three connections is
not physically the same.
VectrexMad!
http://www.vectrex.co.uk