Hi there !

Just thought I'd show a picture of how the bodies of National Triolians that had Bakelite necks differed from all other Nationals (including wooden necked Triolians).

The slot/hole on the top is to accomodate the one-piece bakelite neck and fretboard (T-shaped in cross section).

This photo shows my other Triolian (with it's original wooden neck removed for a reset) showing that a metal strip was soldered over this top slot/hole. I believe this was done to the Triolians that were sent back to National for wooden necks. Notice in this next photo however, that this Triolian has been painted AFTER the metal strip was soldered on.
I believe this guitar was at a transitional stage where National still had some left-over bodies with the extra top slot/hole but had decided NOT to fit bakelite necks any more. They would solder a strip across the hole and then paint the bodies. ie. I don't hink this particular Triolian ever had a Bakelite neck fittrf.

The serial no. on the neck is :  565P
(I don't have a serial no. for the other guitar body as the neck had been replaced when I got it)