engine # TT448
frame # 6380
I've had a look in the register and the frame number is either incomplete or is from 1925. TT448 could be from 1932 but I'm not sure.
If you rechek both numbers see if the engine number could be T1448 and the frmae 56380 as this would be correct for a 1936 250cc Sport machine.
If you can attach photo's or give furhter info this would help.
Cheers, Chris.