[plt-scheme] M-\ multimedia format solved (once)

My Scheme program became a binary file, causing some printing
consternation, and I finally got it back to a text file.  My problem
was that I inserted some lambda's into my file with M-\, but I only
found them all by poring over my 400 line file a # of times.

I recommend that M-f = Find be able to search for lambda = M-\.  
I could paste M-\ into the Find box, but it searched for SPC.

Now the `DrScheme: Programming Environment' manual reads:

3.4.1  Program Files

       DrScheme saves a program in multimedia format by default when
        the program contains images, text boxes, or formatted text.

But how do you find the `images, text boxes, or formatted text',
should you be foolish enough to insert them & forget where?  Now I
know there's M-p to print the file, but it turned a 4 page lpr file to
16 pages, since I my file is so `far to the right'.

I'm very happy to have learned last night the keyboard commands

C-M-;  Comment Out with Semicolons 
C-M-=  Uncomment 

Formerly I used only the Scheme menu items, which is right next to 

Comment Out with a Box

which makes of these `text boxes' which produces `multimedia format'.