Hm.. I know I've seen the Peka name somewhere on newer trailers in Germany- looking around online I see a couple typical flat-sided 70s models- and a lot of references to coupling hardware, etc. The German PEKA [utility] trailer company that shows up is out of Karlsruhe (southwest). It is mentioned in this thread:
Roller Esmeralda 1971 - Das Forum fr Freunde klassischer Wohnwagen und Wohnmobile
The conclusion they reached was that the PEKA name was almost definitely related to the running gear/frame and someone else was responsible for the camper part.
Interestingly, there's a Dutch company called Peka-Wee I found a 1956
vin plate for- Peka-Wee is apparently a phonetically spelled Dutch spin on the abbreviation PKW (Personen Kraft Wagen- personal motor car) The only photo of one I can find is a tiny tent trailer.. amy be related, though. See:
Oldtimer-Forum • Thema anzeigen - Wer kennt "Van Weeghel Parel"?
Anyway, I'd definitely go with Nord-Sud-Plastik [North-South-Plastic] as the maker. I can't seem to find much on them either. Maybe this is a lead:
Nord-Süd-Anhänger Landmaschinen und Wohnwagen-Barta GmbH & Co
Location: Bad Dürkheim
hehe this one's not related at all but cute: