I recently got an Orion telescope with their EQ-1 equatorial mount that's used with various models. The included tray was ok, but there's no organization for your accessories and they end up jumbled. This improved accessory tray has separate slots for two eyepieces and a Barlow lens as well as two hangers for your slow motion control cables. There's also a general tray area for other items.
For this print, you will need threaded inserts and screws, preferably some kind of thumb screw.
3x - M3x12mm thumb screws (thread pitch 0.5mm)
3x - M3 3mm M3-0.5 Threaded Heat Set Inserts
Soldering iron
Heat set tip for M3 or #4-40 inserts
Now, just install the tray with the thumbscrews similarly to the stock tray.
The author hasn't provided the model origin yet.