Does anyone know where I can get a turntable platter machined to my specs

Butterman Tool in Rio Rancho NM should be able to help you. I've been to his shop and it is quite impressive. He's made a custom automotive piece for me where no one else could and as an added bonus, he was the machinist that Andy Payor of Rockport Technologies used to custom machine parts for the first Rockport turntable.

He doesn't have a website but here is the location/contact info:
Johnathan Butterman
504 Frontage Rd NE # A, Rio Rancho, NM 87124
(505) 891-2758

Cheers

What kind of project are you working on? I've wanted to experiment with the platter on my Teres table. 

Well - seeing as you are asking here's the story...
I happen to have a Townshend Elite Rock - the worst thing about it is the rather lowsy phillips motor.
I remember having the pleasure of listening to a DPS 2 when they were first made and was impressed by it's superb timing - akin to a heavy platter deck without oerhang, bit like a Direct Drive or an Idler. In retrospect I attributed it to the motor and platter primarily.
Fast forward to some time later when I got my hands on an Elite Rock - as aforementioned the one real weakness is the drive mechanism.
For many moons I looked for the Berger Lahrs AC Synchronous motor from the DPS - unfortunately Berger Lahrs do not hae it listed, neither would they sell one to me.
As it happened a chap who upgraded his DPS2 to DPS3 spec was selling the motor and power supply so I jumped at the chance to buy it. The things is that the DPS pulley is set up so as to drive a turntable platter by the circumferance - not a sub platter. The problem is that the Elite rock has a platter with a slight angle to it. Now I require a platter that fits onto the Townshend sub-platter machined to the exact size for the platter to be driven at the circumference. I have been wanting to try out a Lexan/Polycarbonate platter as opposed to acrylic due to its low energy storage too. The problem is that polycarbonate is not easy to machine.