Trouble Determining Correct Capacitor Replacement

[ThePlague]

Hello all,

I'm finally getting around to fully recapping my RCA Victor 21-T-8205. I am ordering my replacement axial film capacitors from tuberadios.com and am having trouble determining which replacement to use. The issue lies in any capacitor that is greater than 700 volts. I need 2x .068 mfd @ 1000V and 1x .0033 mfd @ 1000V. The closest that is offered is @ 650V at the correct capacitance. 1600V radial film capacitors are now offered, but nothing close enough to the values needed are available. Does anyone have advice on which to choose or where else to look?