Calling Quinn will help, but he's not going to be able to identify a motor without at minimum some pics of the port or head work. Builders do more than 1 kind of port based on the type of riding the rider does. So it could be anything from an mx port(lots of low to mid power) to a dune or drag port(mostly top end pull). pulling the cylinder is a 1/2 hour job at the most.
1) drain coolant(drain bolt at the bottom or water pump, be sure to remove radiator cap)
2) remove carb
3) Remove headstay
4) Remove base nuts
5) pull cylinder off.
You can just leave the piston on the rod.
If quinn wants pics of the head, i would remove the head before loosening the base nuts.
Lastly, you should sell me those black baja rims! haha.