A True Curiosity - Painted Ambrotype within which is inserted a Small Finely Painted Miniature

This little item confounds me, how did they manage to insert a small painting into this Ambrotype? and when did this happen? The original I think Ambrotype or possibly Daguerreotype (but not I think a Tintype as it failed the magnet test) has as you can see been very naively overpainted, indeed it is almost causes a barrier to you seeing just how handsome the gentleman portrayed in it is and he really is. My instinct tells me that this photograph would of been taken circa 1850, this is mainly due to the style of the preserver and mount it is encased within as well as the Gentleman's hairstyle and fashion. There is you can see some damage to the image in the gentleman's hairline which I hope you can see in the photographs. The painted miniature which has been inserted is small I would think it was originally worn in a locket, and I imagine it to be a painting of gentleman's wife. It is finely painted and I love her hair with the red ribbon set on top and long ringlets at the back, and again I would imagine it be from the same period 1850. The Ambrotype has been opened to insert the photograph which has caused some damage to the glass to the top right hand corner and bottom left, indeed it wasn't until I was looking at my photographs did I notice to the damage to the left corner, the Ambrotype has then been placed within a wooden frame with tape I think placed over it and painted which is the black mount and gold edge you can see. This does have age to it but when it was done I do not know and I have to say this little items feels rather heavy, whether this is because of the frame I am not sure, there has been a metal disc enclosed in the back of the frame which I would think was put there to enforce the hanging which has seen been lost. The photo/painting framed measures approx 4&3/4" / 11cm in height by 3&1/2" / 9cm in width, the Ambrotype measures approx 3" / 8cm in height by 3&1/2" / 7cm in width and the miniature painting measures approx 1&1/8" / 3 cm in height by 3/4" / 2cm in width as seen.
I have tried and tried to find another such example in my research but have completely failed. And so this little item remains a mystery to me on many levels, Firstly why was the overpainting on such a fine photograph so naively done, Secondly how did they manage to insert the Painted Miniature, thirdly who combined these two pieces together and finally when exactly was it done.