The Spitfire is cleaner in general compared to the Lightning. Both have the nice VOXy, jangly, chimey sound. Except forthe tone controls, they are pretty well identical amps.
It is a much simpler design and a people who build them seems to like them. It uses one less tube as well and would make a good beginner project.
Both are single channel designs.
The TC-15 in contrast, is a 2 channel design with an EF86 channle and closer to an AC/DC-30 & AC15 all at 15+ watts in one amp. It is more complicated that the Spit, the Lightning and the 18 watters.
No Spit clone happening but there is a layout here.
http://members.shaw.ca/house-of-jim/Images/schematics/Matchless%20Spitfire%20Wiring%20Diagram%20Rev%202.pdf