Tail lights inside or outside

Tail light question. There are two different types of tail lights.....right?
One has external screws to keep the lense on the assembly.
Another has internal screws to keep on the lense.
Which years use which? I am confused.

My reason for asking is a Tiger I am working on has one of each.

Thanks Mr. Tooth. This car is a '65

Mike

Mike mine are on the inside on my 65

The external screw tail light were late in MKIA production and went into MKII.

Got it, thanks.