Unknown VW radio faceplate and stereo “lock” sticker

[70bus]

Picked up a working Sapphire XIX recently - the faceplate was wrong for my dash (of course) so I found a good prospect on eBay. It had the necessary am/fm slider bar, but it also came with extra holes and a sticker

Faceplate reads 13 D4 0056C0 3 on back

Hole at bottom right Glenn told me was for reception trimmer; one at upper right is what? I see radios w town/country switches but those seem to be sliders. Saw a comment that XIX come with t/c but there is no slider on mine.
There is a small hole in roughly correct place but apparently nothing down there to push. Accidentally put pic turned sideways - hole is at lower right in pic. :p

So am I missing the t/c mechanism on my radio?
What is the ‘stereo lock’ mentioned on bigass sticker? Variant of t/c?
And what radio did this go on?

Apparently last owner was into Ghias, so it might be a clue. Faceplate goes in hole on my 70 bus, so we’ll see if it fits with radio attached.


I wonder if this radio had the same sticker, now faded.

_________________
Craig K
70 Neunsitzer
65 Pritschenwagen
"If Von Dutch was alive, he'd walk in there with a pistol and shoot these people." - Robert Williams

Raoul the 65 singlecab

Karl the 70 nine-seater