The late 70s / early 80s Philips Benchtop Test Gear like PE1539 Series, PM6620 Series, PM2527, PM6670 Series etc. all share similar construction, I like to think of as "soft shell, hard core". Soft aluminium top and bottom cover, metalized plastic front and back bezel. The rest is pretty sturdy. I ended up with two Units with missing bezel / cover, that obviously had a harsh life. Have seen more on Ebay with busted Bezel. I would like to publish my 3d design files, so you can give your Units a second life. Maybe you have similar stuff to post below? I had both bezel sizes printed for my units, they look and fit great, see below.