Drop-in resolution
ETA 2892-A2 vs Miyota 8205: do they swap?
Whether the ETA 2892-A2 and Miyota 8205 share a case, and what changes if you move between them.
Close in diameter, not a drop-in. The ETA 2892-A2 (25.60 mm x 3.60 mm) and Miyota 8205 (26.00 mm x 5.67 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 ETA 2892-A2 is the slim upmarket automatic, base for many chronograph modules and higher-end pieces. The Miyota 8205 is the day-date member of the 8200 family, with a weekday disc alongside the date.
They differ in diameter (25.60 mm vs 26.00 mm), height (3.60 mm vs 5.67 mm), beat rate (28,800 A/h (4 Hz) vs 21,600 A/h (3 Hz)), calendar layout (centre seconds, date at 3 vs centre seconds, day and date at 3), winding behaviour. Same 25.60 mm diameter as the 2824-2 but only 3.60 mm tall, a full millimetre thinner. It is a slimmer platform, not a drop-in for a 2824 case, because the reduced height changes hand heights and case seating.
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.