Try e-gunparts.com
25-75 USD or so
$50-$150 or so. Depends on condition.
5-150 USD depenidng on specifics.
This Model 676 was equipped from the factory with both a .22lr cylinder and a .22 wmrf cylinder - depending upon condition and barrel length (12" barrel commands a 20% premium) value will range from Excellent - $275 down to Fair - $75.
Try e-gunparts.com, gun shows, internet, want ads.
No such model number in the S&W line
Excellent condition: $325 fair condition: $150 Add $25 if you have both the .22lr and .22wmrf cylinders.
Divide it by 26.
I bought mine in 1977.
25-125 USD. Try gun shops, gun shows, garage sales, want ads, e-gunparts.com
676 can be written 676 ----- 1
Since 676 can be divided by 2, (676/2 = 338), 676 is an even number.