It depends on how the rifle started it's life. There have been a more than a few SR-9's that were aftermarket turned into T's and TC's (still using the old SR-9 trigger packs) and are contraban since they are in violation of the ban.
The SR-9 goes for around $2400, the factory T for $3500 and the TC for around $4200. If the rifle is a aftermarket SR-9 in T/TC clothing, then run since chances are it's in volation of the import ban.
Note: Only Differenace between the T and TC is the MSG-90 or PSG-1 butt stock. These rifles were imported/ allowed to have pistol grips since they were target rifles, unlike the SR-9 sold as a sporting rifle. To add the pistol grip to a SR-9, you have to add USA parts (922), and this rules out using the PSG-1 trigger group.
www.hkpro.com/sr9.htm