Need help finding these chainring bolts
 

I am trying to put a 1972 Peugeot P8 E back together and the only thing I am missing is the chainring bolts that hold the crankset together. I have not been able to find the originals so I am hoping someone on here can tell me what size they are or if other ones from another crankset are interchangeable. Thanks.

Here is a pic of the crankset.
Attachment 194299