When you say the frame cross members are protruding, you are referring to the ones above the gearbox?
The radiator is the classic Peugeot shape, but the round/hexagonal things at the top and bottom i have not seen before on a Peugeot, but it could have had a new core fitted at a later date. I guess the rad cap/filler could be the same thing. The rear springs running under the axle is rather odd and i cant think of where i might have seen this before. It could also be a later bodge with springs from something else.
Very interesting, but i really dont know much about the early Peugeots. Cel, by a process of default (and because you own one), you are now the world expert. Does yours have a chassis number?