I have form with this struggle:
Turning a cast iron stove into an espresso machine holder? It scrubbed up nicely (more here) but they are really going out of favour due to air pollution nowadays despite Hygge
Then, trying to restore a 1920s era Kaffe kvarn in a Nespresso world?
Or my latest find - surely I can mash-up a 5 Zloty (€1.25) Zenit 11 SLR camera with a new digital back?
My daughter, however, has no trouble justifying my retro modded iMac G3 - she can start it up and put in some DVDs received from her grandparents with no problem!
As for me - maybe I need to embrace joy in having old restored junk even if I can't use them - sometimes good design is timeless, it's enjoyable to use my hands on a project, and it's allowable to clutter modern life with an appreciation of how we got to this point; that should still fit in the KonMari regimen.
Happy junk-hunting!