Afraid I can't give specifics, but my neighbor did a beautiful and seamless job using the type of product one buys to make molds of the hands of children. You have the child put his hand in this "rubber-plastic" product (available at Michaels) and then pour plaster of paris into the resulting mold. Well, you take the "rubber plastic" product and press to over an intact part of the frame that looks like the missing piece of frame. When you pick up the product, you will have a mold of the detail of the frame. Pour in plaster of paris and let dry completely. Peel mold off and you will have and exact replica. Just glue piece into empty space. I really, really, looked at my neighbor's frame and could not see where the old decoration left off and her repair began. Good luck!
You can do the same thing using silicone or even hotmelt glue gun. give the part you want to copy a spray of Pam before covering it with water you use so that it releases easily. Let it dry and pull off carefully. There was a good posting on this today on the email that I received, here is the link to it.
You would need to make sure that you lubricate it. You can still use the bondo for plaster or wood for repairs or even use silicone for the repair, it won't look any different once it is repaired.. I have both plaster and wood frames to repair from damage due to humidity in my basement storeroom this summer. I can't even find the piece for the wood frame that fell off, the plaster just crumbled.
You can find it in automotive sections or auto parts stores. Make what you think you will use and use it quickly, it sets quickly. Follow the directions for the best results. Bondo that is left in the container will keep well for many other uses in the future. Hubby used to work on a lot of cars when he was younger and used it back then with no problem.
Afraid I can't give specifics, but my neighbor did a beautiful and seamless job using the type of product one buys to make molds of the hands of children. You have the child put his hand in this "rubber-plastic" product (available at Michaels) and then pour plaster of paris into the resulting mold. Well, you take the "rubber plastic" product and press to over an intact part of the frame that looks like the missing piece of frame. When you pick up the product, you will have a mold of the detail of the frame. Pour in plaster of paris and let dry completely. Peel mold off and you will have and exact replica. Just glue piece into empty space. I really, really, looked at my neighbor's frame and could not see where the old decoration left off and her repair began. Good luck!
You can do the same thing using silicone or even hotmelt glue gun. give the part you want to copy a spray of Pam before covering it with water you use so that it releases easily. Let it dry and pull off carefully. There was a good posting on this today on the email that I received, here is the link to it.
https://www.hometalk.com/diy/repair/furniture/repair-that-missing-trim-37624897?
Repair That Missing Trim