ikar01
Could they be 3D printed?
They could be, but would likely be almost cost prohibitive to be done by a commercial resin lithography printer. It may be more suited to a more home-based filament printer. That would also likely preclude printing a rope cable twist.
Hutch6390
It appears that all the Atlantic PE stuff is now only available from Starling Models (starling-models.co.uk), but Atlantic still seems to be in business - can't hurt to drop him a line.
Peter Hall of Atlantic used to be the patternmaker for White Ensign Models. After WEMs demise Peter was able to claim many of the resin masters in the old WEM line. He has remastered some and has drawn new PE. Tom's Modelworks got most of the old WEM PE products and still market them under the WEM brand.
Rescaling PE is often not as simple as changing the magnification number on the copier and hitting print. The lines on the original master may have been drawn at the limit of the technology and when reduced they may not etch successfully. Or they may be out of scale large The graphics designer needs to adjust the line thicknesses for the final product scale.
I have done some home-brew photoetching on sheet brass with Ferric Chloride (FeCl) from Radio Shack [they've been out of business fror how long?]. Caution FeCl eats metal and stains skin, clothes, and counter tops. Use care when using and don't use your wife's/mother's/girlfriend's/significant other's good stuff you will never hear the end of it. PPE is STRONGLY recommended.
I used rub-on circuit board etching solder pads, trace lines, and similar. I also used rub on letters and numbers. You could also likely use any of the rub on graphic items such as trees, cars, etc. Rub them on sheet brass, I used 0.010 and burnish down well. Spray multiple coats of paint on the back side as a resist. Color doesn't matter - you want it thick. Put in a bath of fresh FeCl. It took about 4 to 6 hours to etch through Use plastic tweezers/tongs to manipulate the brass sheet because the FeCl will eat through metal ones (surprise!). Rinse well. The resist on the back can be removed with a wash of lacquer thinner if needed.
I found that there was a limit to the line thickness which I could successfully etch, It was about 1/16 inch. Smaller and I'd often etch through. I tried some etching resist material which could be printed using a laser printer then ironed onto the metal. Results were less than satisfactory and I was still line-width limited. I know Micro-Mark sells a home PE kit. Never used it -- don't know how well it works