Homebrew PCBs

Hello,

 

A while ago I bought some vintage PCB stock from 1973.  I was really excited
about this as it allowed me to go the last mile in making a reproduction
look authentic.  However, I have discovered to my dismay that the toner
transfer process is not working so well with these boards.

 

I've tried three media with my iron (I don't have a laminator):

 

Blue PCB transfer sheets.  They stick wonderfully to the modern stock but
not at all to this vintage stuff.

Yellow toner transfer paper.  Worked on the first two boards mostly, but now
won't stick to any of the others I have at all.

Magazine paper.  This sticks and I get 90% of the image, but that's it.  And
only with much greater effort than usual.

 

I have scrubbed these boards with comet and a scothbrite pad.  I note even
after doing so I still get a fine red powder residue when wiping with
acetone.  So I'm wondering if maybe this copper has just kinda gone bad over
44 years.

 

Another question - on a couple of boards I've used permanent marker to fill
in gaps, but the etchant always eats it away like it wasn't there.  Is there
a particular brand I should be using?   This has happened with both
vinegar/peroxide solutions and FeCl.

 

Thanks!