Seriously, is it me, or are there just next to no good places to get vintage kids clothing? There was one rack of kids stuff at a vintage store in Huntington, mostly old t-shirts and Tufskins. [here it is on Google Streetview, with the rolling rack outside the door.] Stinky & Minky used to have a shop in the Village where they'd sell vintage [now it seems they're just doing wholesale of vintage-inspired designs.]
Maybe I've just been looking in the wrong country. Petits Habits is a Swiss outfit specializing in kids clothing from the 1950's to 1980, with an emphasis on "la mode italienne." They have only new old stock, unworn clothes in excellent condition, and it's kind of expensive, but hey. It's like Didier Ludot, but all for kids.
For example, just add a leopardskin hat, and the short-sleeved boy's suit on the right would be perfect for dressing your kid up like an old-school African dictator. Or for that Jerry Stiller-in-Boca look, try the loungewear-looking ensemble on the right. They're both like EUR139 [$US10,000].
The scale's off on these two dresses [compare the hanger.] The black and white dress is for 9mo, and the Beverly Hillbillies-go-to-Portofino costume is for 4yo. They're EUR99-139.
Overall, it's an awesome, time warping mix of "they sure don't make'em like they used to" and "you've come a long way, baby." They really did dress kids differ'nt back then.
Petits Habits [petitshabits.ch via, I forget]