This isn't exactly what you wanted but with a little practice you can do the entire file in just a few minutes. Five fixed slots and 5 arrays will fix 44 parts
To prevent accidental mistakes, I add a box off to one side, put the original file in the box, then when I make a mistake I can copy the original part.
When shrinking I don't include the original file.
The plywood thickness .110 is typical for 3mm so the reduction is 88%; I sand both sides first so most of the time I use .1085 to get a snug fit [86.8%]
Most of the slots are either .125x.5 or .125x1
The easiest method I can think of is to fix one then do an array copy of the entire part
The base is symmetrical, I would fix one side, draw a vector down the center [top to bottom] erase one half then do a copy about.
For the rectangle with 3 slots you can copy one fixed slot then copy and paste one on top of each of the three, deleting the original slot.
The hardest ones will be the 8-slots that form a circle; I would select and move the part so the center of the circle is over two crossed vectors or guide lines, erase all but one slot, add fillets, then do a circular array around the center point of the crossed vectors/guide lines.
The slot in the ornate parts with the circular slots is at a 45 degree angle... just grab a copy of one that is horizontal or vertical, hit the 9 key to rotate it 45 degrees then drop it on top of and remove the existing slot.
Hope this helps.
You will get old if you live long enough!