UPDATE: I'm working on splitting out the forward red buttons as a separate body. I'm running into complications using Boolean Intersection (errors from F360) and hope to make adjustments to my train of thought to enable the process. From what I've found, it would be quite challenging to split out the button segment in Tinkercad. Just as the aft latch structure is a single part, the current approach is to make the button structure a single part. This would make it easier to segment each of those in a more controlled manner, allowing for full function as desired. It might take me a day or two to get my head on straight.

m18 main body.jpg
The above is a screen capture of the F360 window showing the primary body.

m18 internals.jpg

This one shows the main body ghosted with the single piece latch assembly previously constructed and the newly constructed single piece button assembly. As you can see, there are no fillets in the new section. I'm working on figuring out how to use Boolean Intersection without angering the program.