Omega caliber 320 321 27CH Spare Parts new old stock. Check fit by the following part list:

Part no.               Part name:                                                          Caliber fit:      
320-1100 Ratchet wheel 320 321
320-1101 & 1102 Crown Wheel & Core 320 321
320-1104 Click 320 321
320-1105 Click spring 320 321
320-1106 Winding stem 320 321
320-1107 Clutch wheel 320 321
320-1110 Setting lever spring 320 321
320-1111 Yoke, Clutch Lever 320 321
320-1112 Set Spring 320 321
320-1208 Mainspring 320 321
320-1218 Cannon pinion 320
321-1218 Cannon pinion 321
320-1224 Center wheel with cannon pinion, H0 320
320-1240 Third wheel 320 321 
321-1243 Fourth wheel 321
320-1243 Fourth wheel 320
320-1246 Minute wheel 320 321
320-1316 Jewelled pallet fork and staff 320 321
320-1321 Balance Staff 320 321
321-1708 Minute-recording runner, mounted 321
320-1710 Driving wheel for chronograph 320 321
320-1715 Pillar wheel 320 321
320-1720 Operating lever, mounted 320 321
320-1725 Sliding gear, mounted 320 321
321-1730 Operating lever spring 321
320-1732 Sliding gear spring 320 321
320-1751 Pusher spring for zero action 320 321
320-1757 Pusher stem for cronograph 320 321
320-1758 Pusher stem for zero action 320 321
320-1766 Minute recording jumper- old 320 321
321-1779 Switch mounted 321
321-1783 Hour hammer 321
321-1784 Operating lever for hour hammer 321
321-1788 Hour recording runner 321
321-1791 Driving pinion (hour recorder)  321
321-1792 Friction spring for driving pinion (hour recorder) 321
321-1794 Hour hammer spring 321
320-1757A Pusher stem for cronograph 320 321
320-1758A Pusher stem for zero action 320 321
For other parts please check my other listings or contact me and I'd be glad to help you.
 
The item you are buying is a part of our substantial stock of vintage watch parts from over 40 years of professional practice in repairing watches and clocks.
Our stock includes brands such as Rolex, IWC, Omega, Zenith, Longines, Movado, Tissot, Bulova, ETA, Valjoux, and others so feel free to inquire about a particular part you might need and we will be happy to check our inventory for you. If we find the part you need we can list it on eBay.
If you are interested in buying more than one item, we can combine your shipping at the cost of one item shipment.
Keep an eye on our selling activity as we have many more interesting items to list ranging from vintage watches, watch parts, and tools.