I have 3; one domestic and an offshore 858OT and 858OTB.
I will have to take a family portrate and post it later.
I know that domestic production run was just six years; 1978 to 1984.
I have no idea why the production run was so short.
Taylor-Schrade brought the 858OT back in 2004, after buying the Imperial-Schrade intelectual properties, and all the brand names they had, both in and in some cases, out of production for decades.) After Taylor sold out to BTI in 2014 or 2015, BTI still makes the 858OT after 22 years and counting, since Taylor brought it back., They even came out with an upgraded 858OTB (also in production), featuring genuine saw cut bone covers, and 9CR18MoV ("440c equivalent" ... (note quotes.) blade steel. The 858OT has 7CR17MoV ("440a eqivalent") blade steel.
Speaking of blade steels, ALL U.S. made 858's have stainless (likely 440a) blades, with or without the "Schrade+" stamp.
Why Schrade US only saw fit to produce it for six years is a mystery to me.
The vintage 858's all have Swendon Key construction. All the offshore made have pinned construction.
The Delrin on the offshore knives are different colours... and the "saw cut" lines per inch are also different from the USA made knives to help prevent the offshore knives from being sold by ... unscrupulous ... sellers as a higher price domestic knife. The blades have different tang stamps, and on the offshore knives the secondary blades have a tang stamp (the secondary blades on the domestic knives do not have any tang stamps) to help prevent the offshore blades being used to replace a broken or worn out blade on a domestic made knife. Of course any such blade transplant would also require converting from keys to pins. Taylor did not buy the tooling to assemble and diassemble knives using Swendon Keys.
(Since no other cutlery company has used Swendon Keys - even after the patent expired, and before Imperial- Schrade went bankrupt, and/or after the bankruptcy, I suspect that tooling went to a metal recycling company, or they may have been reconfigured for a different purpose ... if that was even possible ...)
I am pretty sure Camillus bought most of the Imperial-Schrade tooling located in the USA. (No clue who got the tooling located in Ireland and Brittian.)
From my personal experience, the offshore knives are every bit as good as the USA made knives ... potentially more durable, since they eliminated the weaker Swendon Keys, in favor of the stronger (and reparable) pinned construction.