Well, Tom at MBUSA kindly replied with a diagram showing a 3 point inertia system, so the car needs a point at the B pillar base. There are no carpets in the car, but I shall look again at the post. I am quite surprised it had inertia belts, at least that means they should not be too pricey to replace (unless I go for originals)

Again, it depends on what year of car. For example, a W108 sedan could have had 4 different seat belt types depending on year - Kangol, Hickok, strange clip together ones, or retracting... the Classic Centre is going to advertise the latest version, or more likely an even later retrofit.

And yes, you do have a mount somewhere at the base of the b-pillar. It had to have been there.

You're right, they are later replacements. They are also $444 each. Tom kindly offered me a discount though, which was generous of him. I don't think I'm able to spend that kind of cash, will look for alternatives.

FWIW I find the later replacements to be hideously ugly and look very out of place in the older cars. But restored Kangols aren't going to be any cheaper. But at least they would look right.

I am not a fan of the look of most replacements, but I have this company in mind, good looking, nice buckles, colour choice, chrome fittings, inertia reels etc:
Seat Belt Gallery | Mercedes Seat Belts – Quick Fit SBS Ltd

Does anyone know where the buckle should sit in relation to the person wearing the belt? For example, on a modern belt, the latch is right down by your side, but on an older buckle system, should the buckle be near your belly button or nearer your hip?

Thanks

For 3 point belts, the buckle should be by your hip. As you noted, this is how the are used today. And that also matches the instructions for my Kangol front belts from 1968.

__________________
1968 220D, w115, /8, OM615, Automatic transmission.
My 1987 300TD wagon was sold and my 2003 W210 E320 wagon was totaled (sheds tear).

Thanks

I think most of those look good. The exception would be the 111/112 coupe, which I think looks atrocious in the manner that they mounted the B-pillar shoulder anchor. I'm thinking it should come in from the top of the window sill, not the side sticking out like that. Looks horrible from the front, and really looks horrible if you look at the back seat.

Ok, I've found the lower mounting points. they are not where I was expecting them to be..they are a good 6 inches forward of the B post pillar base. They are in the sill, which makes it awkward for fitting inertia reels unless I put an adapter plate in the B post pillar base and move the mounting point. Seems an odd place to put them, as it means anyone getting in and out of the back could get tangled up in the belt. Not such an issue I suppose if you don't use inertia belts, but even with non inertia ones it still intrudes into entry and exit..

I do recall a lot of griping from people who rode in the back seats during that time. There was always a bit of a wait while they threaded their way past the front belts. No one thought anything of it. It was just something you had to do.

What was really irritating about them was that those in the front rarely used them anyway but you could not take them out and still pass the annual safety inspection.

Seat belts lasted a long time back then. Of course anything that is never used tends to last.