Not too mysterious.... looks like the original Mavic Monthlery rims with the remains of the original Mavic transfer. This rim was introduced in 1959 I believe so it was top of the line and perfect for the PX-10 which used these rims up to the early 1970s.
Dimpled rims.... Work of the devil lol. I've got some Superchampion rims which seem to have a random selection of dimpling. Maybe it was a country thing as UK sprint rims were usually never dimpled.
Cheers guys, non eyelets and a diamond shaped decal in white with a dark blue pinstripe surround and a central blue band..did Mavic do anything like this..I haven't seen anything similar.