1967 911 Gearbox seals

I am rebuilding gearbox. I have run into a problem with the input shaft seal at bellhousing. Oldseal is a KACO DS 2240 11/16/2 Flanged seal. Porsche says they changed to KACO DGS22.40 12/31 RF81. The new unflanged seal if positioned at either end of the bellhousing causes the rubbing face of the seal tro be mis alligned from the original part but also mis positions the throughout bearing guide.
Porsche Cars of N A is silent on the subject. They refuse to answer local dealer questions and refuse to answer direct questions.
Does anyone know where to get the proper seal?
Does anyone have a mailing address and contact for customer service at the Porsche factory in Stuttgart.
e-mail reply to rschreter@schreterassociates.com
Thanks for your help, I will post solutions when I find one.
911bob

One thing I found in the seal world is that most seals are metric. I go to a local seal supplier (sells bearings etc. to industry) and check out their supplier's catalogs. Good chance you can find a seal that will work. You need to know the seal outer diam, shaft diam and thickness. Best of luck. Bryan