Simon Mole bought one of his 4005 basses at the Southeby auction. Generally, you do see more 4005 basses from 65 to 68 than 4001's for sale.
You can account that due to the 4005 being an acquired taste, and along with the 4001 being the classic Ric bass in very limited numbers from this period.
..funnily enough when I bought John Entwistle's 4005 there was also a mapleglo 4005WB up later in the sotheby's sale (which The Who's guitar tech Alan Rogan told me he found for John in the 1970's), it was VERY beaten up though, as I remember - I wonder where that one ended up??
