Thanks, Apophenia - I like the floatplane, too.
Here is what might be considered the ultimate development of the T-1, the T-4M, in two versions. Both were intended for the LARA competition eventually won by the OV-10 Bronco. The T-4MA was a conventional twin, whilst the T-4MB had a twin boom fuselage with a large central pod (similar to the OV-10 and Convair Charger).