In an attemp to help date these.......
OLDEST
1 Federal shield, Celebrated stamp, spear and common nick
2 Kerry's knife
3 worn clip point, Sheffield England stamp
4 Mint spear point, long pull, Sheffield England stamp
NEWEST
Quote,
"The first knife with the celebrated stamp, no England, no Sheffield, spearpoint with common nail nick and ordered with a federal shield ( most of these IXL lockbacks had no shield ) is about mid to late 1800's up to 1880 or so. A used and pitted blade, mostly full and still nice and tight. The locking bar notch in the tang on these early examples sticks up extremely proud of the bolster when closed. In later knives it got more flush over time, and by 1890 or so it eventually became flush with the bolster in the closed position from then on.
The next knife stamped Sheffield England with the well worn and pitted clip with matchstrike pull is from about 1890 to 1920, but through experience and the stag complexity, I know it is a lot closer to 1890 than 1920. Perfect lockup, but some side to side play common in all these long early lockbacks made by any company. These are all
4 9/16" knives.
The last example stamped Sheffield England bearing the spear with a long pull has the same stamp as the last knife but judging by the stag, it's non fluted bolsters, and having handled many over time, I know it was made a lot closer to 1920 than 1890. Most of the really complex stag was gone by 1900. Not only was this example never used, it wasn't even handled or opened. It literally sat in a top dresser drawer it's entire life. It could hardly be opened when I got it due to the dried oil in it's joint and locking mechanism. Even now the lockbar can barely be pressed down and the blade is extremely tight even while rotating open or closed. There are barely no rotation marks on the tang, and I put most of those there. The blade retains it's original black (crocus) polish on both sides along with a few peppers and that one nasty spider on the reverse. It is in remarkable condition overall.
With these three knives and the spectacular example posted by Kerry, you have here a good visual history of several different versions of the same Wostenholm lockback built between the mid 1800's through the 1920's.
There are 5 images each of the first two knives, in order, and then seven of the last one"
First knife
Second knife