Problems with the alignment of the top and bottom sides

Hello,
I have great difficulties combining photos from the top and the bottom of the following model:
grafik

Since the model looks very similar from both sides, the alignment does not work correctly even with tie points and I either get two separate components for the top and bottom or a mix of several models, e.g. like this:

Can someone please give me a hint on how to create this cultural heritage object with RealityCapture?

Many Thanks,

Armin

Hi, Armin, can we assume that in this situation, you cannot use a scanning spray? if you can that would probably be your best bet. If not then try using control points.

Edit: Sorry i now see you have tried using control points, are you using cross-polarization? can you share some of your images?

Hi Wallace,
Thank you for your suggestions. We have used an anti-reflective spray for the black parts of the model as they are painted and therefore more protected. We were unable to do this for the brass parts.
How many pictures would you need for a trial? Could I upload them somewhere?
Best regards,
Armin

Sorry, I forgot. We are not using cross-polarization. Instead we have a least a polarization filter for the camera.