Drop-in resolution
Sellita SW330-1 vs Miyota 9075: do they swap?
Whether the Sellita SW330-1 and Miyota 9075 share a case, and what changes if you move between them.
Close in diameter, not a drop-in. The Sellita SW330-1 (25.60 mm x 4.10 mm) and Miyota 9075 (26.00 mm x 4.92 mm) are near in size but differ in height, dial feet or layout, so moving between them means a new dial, hands and often a case adjustment.
The Sellita SW330-1 is the Sellita caller-GMT automatic, the drop-in alternative to the ETA 2893-2. The Miyota 9075 is the Miyota true-GMT (traveller) automatic, in affordable GMT travel watches.
They differ in diameter (25.60 mm vs 26.00 mm), height (4.10 mm vs 4.92 mm), calendar layout (centre seconds, GMT 24h hand, date at 3 vs centre seconds, true GMT 24h hand, date at 3). Built to the 2893-2 GMT footprint at 25.60 mm x 4.10 mm with a caller-style GMT hand and date at 3. It carries four more jewels than the ETA (25 vs 21) and is the standard donor when a 2893-2 is unavailable.
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.