I'm doing a TruSonic recone right now, for SixCats... just waiting for parts.
As was stated above, they're not any harder than any other vintage woofer to recone, with the caveat that OEM cones are not really a viable option at this point, IME. Even those NOS cones are as brittle and fragile as the ones already in the speakers. I don't know of anyone making "original design reproduction" cones for these, either. However, there are vintage-style cones (ie, Jensen, JBL, Altec, etc) that will work and sound fine, when they're set up and installed properly. I've been able to functionally match all of the Trusonics I've seen here on the bench...
Which model Trusonics do you have? What size voice coil (2", 3", 4")?
Regards,
Gordon.