Or, you could try converting the links to text first by Edit/Replace
Find =
Replace With %%

Then Edit/Replace the cell references you want and convert the text back to
formulas with
Find %%
Replace With =

That didn't really help, but now I know that just _one_ of these sheets has
1600+ formulae and 6000+ occurences of $978

However, the problem still occurs when I do the last step.