What I'm thinking he's saying is that you need a spring drum, because the mainspring inside of the one in your machine has broken somewhere.  Does this older gentleman have this part?  This should still be a fairly common typewriter. You may not find the part for the five dollars, nor will you be able to pay five dollars for the repair.  The expenses so far incurred on your purchase will come out to be considerably higher.  There are others of this genre that are also called "Office Riter," "Letter Riter," and "Quiet Riter 11."  They all should share the same kind of part this man says you're needing.  How proficient is he at fixing typewriters?  Was he a typewriter mechanic?  Is he a long time typewriter hobbyist?  That is what I am.  I am hoping you won't come out too much more expensive on this deal, and that your typewriter will work properly.  Let me know something.

Just so you know, the mainspring is what makes the machine go -- it's what pulls the carriage from right to left and enables you to type. So without a working mainspring, you don't have a working machine. You'll need to find a "donor body" Remington, like one of the machines TypewriterKing mentions. So this could prove to be a much more expensive proposition than $5. (You might find a perfectly good other Remington for not a lot more than that, like less than $50, in which case your $5 machine will sit unused.)

Post on the parts subforum here -- maybe somebody has a parts body Remington from which they can harvest the mainspring assembly. Good luck!