1. 21j movement
http://www.trustytime88.com/index.php?main...;products_id=39
This one has the old cyclops and thin date font. The subdial @9 should be recessed. 'Synthetic sapphire' sounds mineral glass to me, but you should check it with Andrew. The 6 font looks a bit odd. Also the crown is a bit too thin. The case back inscription is way off. No AR coating.
2. low beat 7750 (old version)
http://www.trustytime88.com/index.php?main...;products_id=90
This one also has the old cyclops and thin date font. The subdial @9 is recessed and more correct, too bad they placed the L Swiss Made L incorrect. The glass is supposed to be sapphire. The 6 font look better to me. The crown looks too thin. The case back is still incorrect, but looks better than the 21j version caseback. The low beat 7750 is notorious if unserviced. No AR coating.
3. high beat 7750 (new version)
http://www.trustytime88.com/index.php?main...roducts_id=2437
This the latest release of the 104 and almost 'ultimate'. The high beat movement is more reliable, especially after servicing. The crystal is sapphire and has single AR. The subdial is recessed, altough not as much as the gen. The cyclops and date font are much improved. A real difference with the other 2 versions. The crown also looks a bit thicker.
The only annoying flaw is the position of the L Swiss Made L, which is too close to the 6. The inscriptions on the case back are difficult to see on the pic, but at least they've added the serial number. Don't know if the OP number and BB number have been improved.
Qualitywise I would choose the 3rd. This is the most accurate version to date. Too bad of the L Swiss Made L thingy, but I could live with that.
I would only trust my own watchmaker for waterproofing....
Good luck!