Model M1911 has two features that are add-ons.
Two detail pieces were made, finished, and painted separately. This was done to allow for greater detail and nicer finish. It would have been difficult to mold them into the main portion of work and make them look correct. These portions were removed from the main work.
It is time to attach them to the main work. The two pieces in question, viewed from the bottom:
Automotive-grade double sided tape (made by 3M) was applied to the backside.
The red backer allows for application on the substrate, and is then peeled off.
Next is to place them in their proper location.
Now the details have been added and they look great. The fit and finish has been much improved by having these made separately and added after the fact. The double-sided tape allows them to be removed in the future should that be necessary. There are also permanent mounting solutions available if that was necessary.