3D ring in STL for 18k gold cast

Hello, I would need a 3D model (STL file, ready for printing and casting) of a custom ring. Two reference images attached. SPECIFICATIONS Style: bypass ring, with two gold arms wrapping around the centre stone on each side (as in the first reference image). Intended metal: 18k yellow gold. Centre stone: round brilliant cut, 5.00 mm diameter. Semi-bezel setting, edges protected. Pave: round white CZ, 1.20 mm, along the shank on one side of the bypass only (as in the second reference image with the pearl). Please advise on the optimal number of stones for the finger size. Finger size: 50 EU TECHNICAL REQUIREMENTS - The file must already compensate for casting shrinkage. - Minimum shank thickness 1.2 mm; bypass arms no thinner than 0.9 mm. - Stone seats should be roughed in only, not finished: final seats will be cut by the setter after casting. - Please model the stones inside the file at the exact sizes given, so spacing and depth can be checked. - The centre seat must stay at the standard 5.00 mm, as I want to be able to swap the centre stone in future. DELIVERABLES STL file plus a preview render for approval before finalisation. Thank you