Nick, in all honesty, they look far better than they function. I had one, from new, in my Aero and purchased it at retail price; by the time they discontinued it, I saw NIB (new in box) ones selling for circa £4k+.

Even at retail it felt clunky and poorly considered. Certainly a good example of form over function and personally I wouldn't pay an inflated aftermarket price.

Does your GTN have the dark dash or a silver one?

If you are looking for something retro but functional, I have used one of these in a modern classic:

https://www.cen.uk/blaupunkt-bremen-sqr-46-retro-car-stereo-80s-classic-bluetooth-dab-usb-sd-aux-1

Whilst they lack the 'silver art deco look', they benefit from the lack of flashing screens and neon-esque features of many modern ICE units, which I was keen to avoid in a Morgan as well as any classic car. Blaupunkt offer other retro versions but I felt the Bremen was the closest to what I wanted for the particular classic I was fitting it to.

However, the also offer the:

https://www.classiccarstereo.co.uk/...-car-stereo/blaupunkt-stockholm-400-dab/

And I see a Hamburg is in the works, although this seems less 'Morgan' to me and more 80s JDM:

https://www.classiccarstereo.co.uk/...car-stereo/blaupunkt-hamburg-sqm-23-dab/

If you want more of the deco look, I've heard reasonable things about these (they offer various cosmetic versions, not just the first photo in the link):

https://www.raysmith.co.uk/products/retrosound-classic-car-radios?variant=42504842510558

Personally, all I want is something that streams music/radio/etc from my phone, so as long as it looks good and does that, I don't need anything more.