A TON of people have built it. Probably hundreds. The Lite 2b is the same as channel 1 on the standard 18W, but with a better tone knob.
Another option, which is very similar in difficulty level (easy), is the EF86 Lite. That will give you a little more distortion, with a little bit of the Vox sound meshed with the Marshall sound.
Here's a demo of an EF86 Lite I made for somebody: https://www.youtube.com/watch?v=dj0RL4XVv6A
Thanks,
Josh