[INM@RLM]

Starting at the bottom first, Leo. We don't have to rely on opinions here.

In BA-MA RL 3/4139, along with at least some of those for the Ta 152, you will find the FoWu company-issued 'Kennziffer der Nachbaufirmen Fw 190, Stand von 15.12.1944'. (Evidently a document not available to Peter Rodeike those many years ago. We really need an updated edition of his book in English given the progress in discoveries since.) This document does get a mention though on p.472 of JaPo II.
There:
prefix-35 for the Fw 190 A-8 is given as "Arb. Gem. WFG, Nordenham"
and prefix-38 for the Fw 190 A-8 is given as "Mimetall-Erfurt"

This will also be the source for the statement that
prefix-69 for the Fw 190 A-8 was "Leichtbau Budweis".

While we're here, the Fw 190 D-9 prefixes were listed in this document as:
40 = "Arb. Gem. WFG, Nordenham"
50 = "Mimetall-Erfurt"
60 = "Fieseler'

Where it gets into opinion is that despite the document stating that prefix-40 denoted simply "Arb. Gem. WFG, Nordenham", hence likely implying a single production source, the Werk-Nummer identity evidence for this prefix is that it was split into at least three distinct, separated sub-sequences each of which can be traced to a different physical location. So in my own judgement, the common connection for each of these is that all of the fuselages used were built at Weser Nordenham. (That 190 fuselages were built at Nordenham is documented in the CIOS report already mentioned.) Then, in addition to final assembly of complete D-9s at Nordenham itself, these fuselages were also despatched to a number of other final assembly locations under the Arb. Gem. WFG umbrella. (I already cited the Feb-45 document evidencing the railing of fuselages from Nordenham to Erfurt clearly for use by Mimetall.)

I did not see that data plate reference in JaPo so if you find a page number for it that it would be useful.
There is a photo of the airframe data plate from Fw 190 D-9, WNr. 400255 at Urbanke: Green Hearts p.196. The Fertigunskennz. is MDL which is indeed that for Weserflug, Nordenham.

The practice of building sub-assemblies at multiple different plants to be brought together for final assembly at one location goes right back to the Ju 88 program planning of 1938, so there was nothing new in the concept. However, this was only feasible to the degree that an aircraft had been designed as separate modules. That was a key element of the Fw 190 design but had not even featured on the landscape when the Bf 109 was designed. What was the newer element in this was the transfer of flight testing away from the airfields at the production plants and its dispersal often across more than one testing site. OK, enough I think for one post.