18th century necklace pendants or dupe?

Hello! I have only posted once before here when I mistook a vintage reproduction for antique. I have learned more since then but this piece of jewelry is new territory (I normally collect wood carvings and art).

There are there separate pendant pieces that I am pretty sure go together as one as photographed. Very tarnished and dirty, middle piece is missing one stone, but the others appear present. Used a loupe and definitely lots of shine to be seen through the narrow openings. Very light metal. All hanging together is 3" long.

Any advice welcome! It is way too easy to get excited and see what I want to see lol.

 

@Any Jewelry @kyratango

 

Those look right to my eye.

 

That is good to hear! Thank you. Do you think I should have the pieces professionally cleaned and repaired? I can fix up wood but this is way out of my wheelhouse.

 

Looks right to me too, not that I see any here. I wouldn't mess with this; if it's true to form those missing stones are diamonds.