You are both partially right. I agree with cmetisse that it is related to the Grecav Amica, but in fact it isn't exactly one. That's the reason for the differences to the photos in your archive. And sixtee5cuda is right that it is a Sieberg. The Dutch legislation led to narrowed versions of well known microcars. I know of 1 meter wide versions of the Casalina Bretta, the BMA Amica and the Decsa Lisa (http://www.autopuzzles.com/forum/index.php?topic=21379.0), and of 1.1 meter wide versions of the Grecav Amica and the JDM Abaca. I'm not sure where these Dutch-only versions were built, but I think that the Lisas and Amicas were built by Sieberg. The puzzle car was probably built by Sieberg under his own name after the Amica went out of production.
I feel generous today and give you both one point each.
Do our Dutch puzzlers have more information about these narrow track microcar conversions?
Was the Arola production continued by Waaijenberg after the French production stopped?
Who built the Bretta 1000?
Am I right about Sieberg converting Decsa Lisas and BMA/Grecav Amicas?
Was the JDM City built in the Netherlands? By Minicruiser?
I have a bit information about these.
For sure, Arola sold the rights and tools for the models 14 & 15 to Waaijenberg, and the dutch started again the production of modified cars, narrower, with other doors and a Sachs SC50 engine (later with a gasoline 160 cc Honda), under the names 16, 20 and 40. I think these were just related to different trim levers.
It seems they stopped the old Arola range around 1995 (I've called the Waaijenberg factory, but got only quite vague informations).
I'll know more soon about the Bretta 100, as I know quite well the Casalini brothers. I'll let you know.
I can't tell you for the Decsa conversions, but I have a brochure for the Amica "BMA by Grecav" 1 250, a "revival" of the old 4-wheels version for the french market.
The address of Sieberg in printed on the document : Sieberg bv, based in Aalsmeer, importers for the Benelux...
The JDM 110 City was not based on the Abaca, but on the shorter Albizia, and built directly at the Avrillé JDM factory, in Maine et Loire.
But any additional information would be highly appreciated, as the "invalid dutch/german microcars" are a subject for which I don't know much !