Randy's pickups weren't very loud on Blizzard of Oz. On Diary he may have had something a bit louder when he used the V, but Diary is pretty quiet pickups through a Marshall with the mids dimed and the treble kept low (no it's not a wah!). If you want a BKP to match what Randy Rhoads used, put a Black Dog or a VHII in a Les Paul.
Being a strat, I'd probably try the Holydiver.
I've been trying to figure out what the pickups in his '72 LPC were.
I know that they were stock, but I've heard rumours that they were
som kind of hotter PAFs .. but I'm not sure.
As for the Polkadot V, it was loaded with Dimarzios(Super Dist and PAF)
and the Jacksons had Duncan Distortions in them and a Duncan Jazz
in the neck ... atleast the white one :)
My guess though, is that the closest you can get to Randys sound
is some humbucker with PAF character through a MXR Dist+ and
a Marshall 1959SLP :)