Great find. Here are some differencies I noticed:
Does the Talbot gasket have a silicone bed in the other side like Peugeot's? Talbot's gasket has a region that has been cutted off, near the timing chain end (that really doesn't matter).
The other end of the exhaust gasket is a bit different (doesn't matter, N9T exhaust manifold just has one more fixing point). One of the bolt holes doesn't seem to be larger than the others (for the exhaust manifold guide sleeve, second from right at the bottom), so you'll have to increase the size of that hole or stop using the guide sleeve. Luckily the Talbot gasket has metallic reinforcement rings around the exhaust holes, so it might last even if doesn't have full metallic layers like Peugeot's?
Here are some pictures that I took when I replaced the head gasket of my white Turbo:http://peugeot505.in...age=1&id=images
(4 pages, detailed pictures comparing the original and the Chrysler gasket are on pages 2-4 )
I replaced the old gasket (made originally for the Chrysler 180 and/or 2 litre, I think) with original Peugeot gasket. In my case the Chrysler gasket also had smaller cylinders holes (can be seen from the pictures) but the Talbot gasket seems to have bigger holes just like Peugeot's.