sdr200 part numbers:
Here's a list of Yamaha part numbers for the sdr200, if you have any to add please email me!
Yamaha Part No.ItemOther bikes common with
2TV-1490J-00Jet Needle Set-
1KT-14141-48Emulsion TubeTZR250(1KT)
37F-16371-01Inner Clutch BasketDT200R(37F)
3ET-11610-00Piston RingsDT200R(3ET)
93306-30556Crank Shaft BearingLots!
3PA-15455-11Alternator Cover GasketTZR125(3PA)
3PA-15451-10Clutch Cover GasketTZR125(3PA)
37F-11181-01Head GasketDT200R(37F)
2TV-11351-01Base Gasket
2TV-22110-00Swing Arm
2TV-27211-00Brake Pedal
36F-12450-00Water Pump Impellor Shaft AssemblyDT200R(37F)
90215-12271Washer locktab for clutch nutLots!
93103-10168Water Pump SealLots!
2G2-24512-00Fuel Tank Seal (The little oval one)XS650?
29L-1132E-00Power Valve Pulley(I think same as 350 YPVS)
1JK-27413-00Footpeg rubbers(optional, taken from an SRX600)
90123-06097Power Valve Cable Adjuster Bolt (x1)
3HM-83310Indicators complete-
2TV-83312Indicator Lens-
2G2-24534Fuel Tap 'O' ring seal500LC
47X-24523Fuel Tap Valve seal500LC

sdr200 bearing sizes:
Crank Bearings6305RI
Gearbox Input Shaft - RH Side6204Z
Gearbox Input Shaft - LH Side?
Gearbox Output Shaft - RH Side6202
Gearbox Output Shaft - LH Side6304
Balancer Shaft - LH Side6302
Balancer Shaft - RH Side6203
Replacement Tapered Steering Head Bearings - top and bottom324808-B and 324800

sdr200 parts Yamaha doesn't seem to sell anymore :(
Yamaha Part No.Item
?Fuel Filter!
?Rear Suspension Linkage

Aftermarket Parts:
PartManufacturer/Part NoLink
Rear ShockEMC EMCY02 (Fits SDR200 and 1987-88 TZR250)BB Bikeshop Ltd
VT Norridge
Clutch (Friction Plates)EBC Part: CK2313Wemoto
EBC Direct

Compatible Parts:
Bit's from other bikes, that aren't identical, but fit anyway:
Front CaliperTZR250 3MA or 3XVApparently these bolt on as a direct replacement, though I haven't tried myself.
(I mistakenly bought a 2MA caliper, which definitely didn't fit!)

original sdr200 caliper:

TZR250(3MA) caliper
Front CaliperTriumph
Another direct replacement is a Triumph caliper (possibly from a speed triple):

According to Budgie-mog "it stops on a sixpence"!