A Scottish woman I used to know (& she'll be in her mid-to-late 70's now) used to use the expression "dressed up like a Shillimg dinner". It does make more sense than "dressed up like a DOG'S dinner" which is a more common expression I think, here in the UK.

"Mutton dressed up as Lamb" is another common one of course, but I think I invented the more extreme form of that - "Not so much Mutton dressed up as Lamb, as offal ground up for mince..."