Playing again with Do-335 components. This is the current part collection, some at 14.68 (lanyu) scale, some at 1/10 scale and the Landing gear at 1/6th scale.

Finally discovered that those Gun troughs were actually only Prototype gizmos .. Fitted as place holders for the fitment of the Real guns .
Line /production units Did Not have those things.
Armements were typically fitted at the prep facilities ..once the delivered production models had passed their official flight testings.
Tripped over that studying the He162 which 'had' ejector seats, which along with armaments, were fitted ..only.. after passing flight /quality testings.
As result 'several' Test pilots died in bail out attempts.. because there were no ejectors.

Ok have to ask:
what is a decent (cheap ?) 3d printer to learn with... maybe even print a few bits.. eventually.
Full awareness of the steep learning curve with new software .. with the added challenges of a sketchy contraption
( was an architect for 35 years) never ending stream of 'new and improved' software was/is an industry problem, turning designers into keyboard operators.
My wife doesn't have much to do with me either.. but that doesn't stop her from annoying / interfering .

Thanks for the info - had no idea the troughs were temp items. I thought it was to keep the discharge blast from cooking the cowl.

I'm on my 3rd 3d printer and thinking of butying my 4th-7th technologies over time (those being Prusa (FDM), SLA, CLIP, and finally metal sintering when the price comes down). This is still very much a hobby still, and as such you have to like messing with the printer and software too - if you just "want it to work" its still pretty irritating, ultra slow and pretty low resolution - like the first dot matrix printers compared to a selectric . FDM (fancy glue gun) is most economical. I have a Printrbot Metal plus which is decent, and before that had a Printrbot Metal simple which was fine but smaller envelope, and a robo3d which never printed right for me. My current "pick of the litter" is this one: https://www.prusaprinters.org/prusa-i3/ I'll probably get one even though my current one is fine. If you want something small and cheap just to try out, look at monoprice. You'll also need to be conversant with 3D cad. You can mess around with junk software, and versions of Autocad will work but you can get Fusion360 for free or can join the EAA and get a free Solidworks license that way. If I were starting from scratch I'd just go with Fusion, but I'm pretty wedded to Solidworks after being a long time Autodesk Inventor user (Inventor easier to learn, Solidworks able to do more and more stable). Doing proper 3d design is the only real challenge, but as an architect I doubt that will be a big deal. You have to design for printing too, working around feature size limitations, limited accuracy, part overhangs, part strength, wall thicknesses, heat tolerance, material selection etc. then configure part orientation and print supports in the printing software. I've tried them all, and Matterhackers/Mattercontrol is the slicer I like best. I used Cura for a long time which is good also. Each of the bewildering options has its pros and cons but most of them are free so you can see what you like best. So, its CAD then the slicer, and the slicer will also run the machine (usually with an additional machine control interface). Lots of software, hardware, design and materials handling and finishing to figure out. Since you are a good model maker already, not sure this does that much for you, but its kinda fun in its own right. One cool thing - done in sections you could design and print out a whole airplane... there's a guy that's a good designer who sells the files for some planes done that way.