Doug -
Most target bows back in the day, they came in the same lengths as today's ILF target offerings, mostly in the 66" to 70" length. For draw lengths between 26/27" for the 66" bows were recommended and the 70" models for the longer draw lengths over 30", BW were no exception.
A 68" should work well up to the 29" range (+/-), but with all wooden bows, the model to model variance could be significant.
A lot of the wooden BW target bows, while stable due to the physical weight, were on the slow side and usually (but not always) pretty loud. The metal risered target Widows (1200 series) were also dog slow, but painfully easy to shoot, some people claimed they almost shot themselves - but yes, they did weight a ton!
Viper out.