Drop-in resolution
Ronda 5030.D vs Seiko VK63 (SII): do they swap?
Whether the Ronda 5030.D and Seiko VK63 (SII) share a case, and what changes if you move between them.
Different footprints. The Ronda 5030.D is 28.00 mm x 4.40 mm and the Seiko VK63 (SII) is 30.80 mm x 5.10 mm, so they do not share a case. This is a choice between platforms, not a swap.
The Ronda 5030.D is the reference Swiss quartz chronograph, in a large share of quartz chronographs. The Seiko VK63 (SII) is the reference meca-quartz chronograph for modders, a quartz base with a mechanical chrono module.
They differ in diameter (28.00 mm vs 30.80 mm), height (4.40 mm vs 5.10 mm), calendar layout (chronograph, small seconds at 3, 12h at 6, 30min at 9, date at 4 vs meca-quartz chronograph, three sub-dials, date), winding behaviour. A quartz chronograph at 28.00 mm x 4.40 mm with sub-dials at 3, 6 and 9 and date at 4. It is the go-to quartz chrono module; the smaller 5021.D is its bicompax relative, not a drop-in.
Matching diameter and height is necessary but not sufficient. A donor is only a true drop-in when the dial-foot positions, hand-hole sizes, stem length and calendar layout also match. Two movements can share a case and still need a new dial, re-broached hands or a cut-to-length stem.