I think you have a typo. That would be a 268/760, there is no 258 Autotrol control.
HJ. Autotrol does not make a brass or SS by pass valve, only Noryl plastic. The only brass push/pull is made by Taras or Tomlinson, I can't recall. The SS is made only by Fleck and used for some of their control valves but not all.
All Autotrol and Clack, and some Fleck plastic BPs are made with individual shut off valves for both the inlet and outlet. All plastic BPs are ball valves.
All of them shut off all water into and past the softener by simply shutting the inlet side of the BP with the outlet in the Service position, or open.
That is much better all around than a 3 way manual by pass plumbed into the plumbing and there is much less pressure loss and absolutely no dead ends. The manual 3 way also costs more at today's prices for copper tees tubing and brass ball valves.
An additional problem with 3 ways is that the number of valves are confusing to the lady of the house and sad to say but more and more non mechanical kinda guys.
The only plastic push/pull rod type plastic BPs I know of being sold today are on the big box store brands; Kenmore, GE, Whirlpool, and the plumbing/pump supplies' North Star and the mortonsalt.com and Ecowater dealers.