Trying to find out how long the Kirk model ran. The only example in the DB is a '52. I have what I think is a '53...waiting on the panel to let me know. But there is an interesting watch on Ebay from '64 marked clearly with an M4. The face also has Bulova and 23 Jewels written on it. The hands look like '60's era hands. But I can't find anything in the '60s even close to it.