I want good Profile to easy fit & lock
I have develop 2 part to internal lock & fit.
one part from extrusion & another from plastic moulding
both part material is pp (plastic)
Dovetails and "T"s are pretty common shapes. You might also look at some of the rail designs on guns and rifles for mounting lights and other accessories.
Please consider adding clearance between your parts. Without clearance, they will never fit together. Right now the design looks like it is "line to line". The only thing worse would be an interference fit.