Recursively replace block of code in multiple files using FIND and REPLACE from external files

I'm looking for a script to recursively replace a formatted block of text across all files and directories, with the search and replace text coming from external files. For example:

find.txt

Lorem ipsum dolor sit amet, consectetur adipiscing elit,
    do eiusmod tempor incididunt ut labore et 
dolore magna aliqua. Ut enim ad minim veniam, quis nostrud

replace.txt

Excepteur sint occaecat cupidatat 
   non proident, sunt in 
       culpa qui officia 
       deserunt mollit anim id 
est laborum

And then a simple command along the lines of:

replace find.txt replace.txt /some/dir/*

This one is close but not quite. But it looks like perl slurp might be part of the solution?

I don't care what language it's scripted in, as long as it's common and runs on Linux. Thanks a lot!