u/Major_Plantain_3182

Hi. Can any of you experts help tell me what's going on with the neck of this Tele I just bought. It's a very odd one because it came off a partscaster with a 66 serial neck plate, but the slab board and the odd 20 on the neck end is making me wonder what's going on. Can anyone shed any light?

I'm aware the neck code should begin with just 2 before the month but have seen that some special models had an added number. Could this explain the apparent slab board?