For what it's worth, here’s a narrative describing how I removed the stunt box from my Model 28 RO.  I was a total noob at this, but thanks to advice I received from Greenkeys members (especially John Koster, W9DDD), it was easier than I thought it would be.  With that being said, here we go:

First, I read the article by Irv Hoff in the May 1970 issue of RTTY Journal.  https://www.navy-radio.com/manuals/tty/stuntbox-rtty-7005.pdf     Then I read the Teletype brochure about Stunt boxes:  https://www.navy-radio.com/manuals/tty/28SB-stunt-km4v.pdf    Those gave me a good outline.

Referring to the annotated photo below, I did the following steps.

1. I removed the homebrew “pull ups” at A.  Those pull ups disabled very odd features of my particular stunt box without my need to remove function bars (et al.) from the stunt box.  I removed the pull ups (after noting their particular slots) to ensure that when the stunt box was removed from the typing unit that things didn’t fall out of the stunt box.  I don’t know if this was absolutely necessary, but I did it anyway.

2. I removed the c shaped retaining clip (at B) that holds the lever to the attachment on the horizontal rod, and then when the retaining clip sprang off the post it fell into the gear works.  Don’t do that.  Be careful that the c shaped retaining clip doesn’t fly away.  Once removed, put it in your parts cup, and don’t just leave the clip on your work surface.

3. With the c shaped retaining clip (at B) removed, there wasn’t enough slop in the linkage of the lever to pop it off the post.  So I removed the screw (at E) to the left of where the lever attaches to the horizontal rod.  That screw is not a set screw – it is a through-the-rod retaining screw, so it had to come all the way out in order for me to slide that attachment to the left to release the lever from the post mount.  Once I slid it a little to the left so that the lever pops off the post, I then slid the attachment back into position and reinserted the screw.

4. I then carefully rotated the bottom of the drive gear (at F) toward me, to move the main shaft in the normal direction of rotation (when viewed from the selector magnet end of the shaft the shaft will be rotating counter clockwise) until the lever that was attached at B was in its lowest position (so that the stunt box would clear the lever when the stunt box was removed from the typing unit).

5. I then remove the screws at C and put them in my parts cup.  When the second screw was removed the Stunt box popped back toward me 3/8 of an inch or so.  At this point the stunt box was free to slide backwards toward me, with only two guide pins on either side holding it position via two track slots (at G).  I gently pulled the stunt box horizontally back towards me, maybe with a slight upward or downward motion.  I found that the right side came out easily, but the left side got hung up on the cables at D.  I had to move the cables a bit in order to get the stunt box to clear.

6. Reinstalling the stunt box is pretty much the same procedure.  I started by inserting the stunt box such that the two guide pins on the left and right sides were in the guide slots, then gently pushed the stunt box forward (away from me), working around the cables at D.  When it was all the way in I think I pushed down a bit and the stunt box held in place (did not pop back) while I inserted the screws at C.  I then removed the through-the-rod screw (at B), slid the attachment slightly left, moved the connecting lever into position to go over the post on the attachment (I rotated the main shaft a bit by gently pulling the bottom of the main gear (at F) toward me to get the lever into proper position).  I then reinstalled the c retaining clip at B, then re-installed the through-the-rod screw (at E) to fix the attachment in place.  I then gently rotated the main shaft a few full revolutions (by gently pulling the bottom of the main gear (at F) toward me) to ensure that nothing was binding and that there was no significant resistance while rotating the shaft.  Finally, I reinstalled the pull-ups that I had removed in step 1.

As I was told by others before I started this project, once I had removed and reinstalled the stunt box I’d feel that it wasn’t that big of a deal, and I would now agree.  But without the Irv Hoff article and the specific advice from Green Keys members, it would have been a lot more stressful and more likely that I would have broken something.  My hope is that the description above of how I removed the stunt box in my 28 RO may be useful to others who are removing a stunt box for the first time from their machine.

Paul - ad7i