The Schatz 1000 day clock was not a bold step forward because it just increased the time between winds.
They were able to increase the time from 400 days to 1000 by taking the 400 day movement and putting in a mainspring that held 2.5 times the energy.
You can tell when one was made by looking at the month and year stamp on the back of the movement.
|Schatz Mainspring Anniversary 1000 day clock 21 x 50|
Time Remaining: 1d 22h 39m
Buy It Now for only: $26.49
|Schatz Co 1957 1000 Day Anniversary Clock Model 54 Working Condition|
$75.00 (1 Bid)
Time Remaining: 2d 5h 41m
|SCHATZ 1000 DAY MANTEL CLOCK|
$35.00 (1 Bid)
Time Remaining: 4d 12h 43m
|SCHATZ 1000 DAY GERMAN Anniversary clock 54 Brass Plastic Glass Dome 1957|
Time Remaining: 4d 21h 29m
|GERMAN AUG SCHATZ SOHNE 1000 DAY 2 JEWELS UNADJUSTED 54 MANTEL CLOCK|
Time Remaining: 5d 17h 51m
Buy It Now for only: $140.00
|SCHATZ ROYAL MARINER SHIPS BELL or 1000 DAY CLOCK KEY service repair parts|
Time Remaining: 10d 19h 46m
Buy It Now for only: $18.99