print the thing, glue the left and right pieces in the respective shell sides of the retaliator/recon, glue the front to the RIGHT SHELL ONLY, put the mag release in the right one, assemble like normal, and it's integrated.
Picture shows a FTW setup in a recon, but this will work in a normal spring-based retaliator/recon
Print Orientation: I printed everything except the release right side up, everything with supports (see picture)
You may have to trim the original slot of the mag release.
UPDATE: 12 Feb 2023
made the files actually work, the old version is completely removed
First uploaded 12 Aug 2022
The author remixed this model. Imported from Thingiverse.