Here is the link to the TCDS:

http://rgl.faa.gov/Regulatory_and_Gu...4?OpenDocument

The TBO is not specified...

I assume that you have no desire to place this A/C in commercial service. i.e. Part 135... If the A/C is not in commercial service,
TBO's are merely advisory. I would ensure that the engine is safely flyable. Any A&P can do this. Once the A&P is satisified, fly
the engine until you or your mechanic have reason to question its health.

If you want a self imposed TBO, I would probably pick one between 1200 & 1400 hours. You have a WWII era engine. YMMV.