Sorry for late reply.

Here is what I made for 40 series using window latch mounts. Worked out that the windows are still fully operational and lockable on the slides with a minor adjustment.

https://talk.newagtalk.com/forums/thread-view.asp?tid=802321

Could be mounted on right or left window latch mountings.

More pics here.

https://imageevent.com/vprb/jdsoundgardcabrammount

On the 40 series (55 may be different rail configuration) There is a really heavy duty clamp on mount from JD for holding a monitor, clamps to the curved lip under the right hand front window. It's heavy and very rigid for mounting. Could use that to mount multiple monitors. Only picture I have and does not show the mount that well.

The Shoup mount is here and they have a pic of how it fits.

https://www.shoupparts.com/CC44-Monitor-Organizer

Not sure there may be 2 holes already in that front curved rail but I know in my 4040 there are NOT 2 holes in the back rail under the window which is where the back of the mount sets. I'm like you I don't like drilling holes in stuff.