I have this laptop power cable that's just plain metal shop fodder, it's
    sort of like a Mini-DIN version of a Din-4 connector, only different.
    THE hard part for home making goodies is getting thin metal shields made
    to match an existing part;  If anyone has good ideas on THAT, I'd like
    to know more.

If it's really a mini-din connector style (which seem to be very popular for
larger line-wart style power supplies, for some reason), just buy a mini-din
connector (that doesn't fit) and "adjust" the pins as necessary.  (probably
the easiest thing to do is buy one with lots of pins and break off the ones
that you don't want.)  If necessary, disolve or burn away all the non-metal
parts, and you'll be left with a shield...

BillW