You are correct about the build date. Your engine was built June 26, 1986 at the Consolidated Diesel plant in Rocky Mt., NC. That was the primary building plant for B and C series engines. Your engine is a CPL 0767 which was a common early model. One unusual feature of that CPL was an odd exhaust manifold with a compound angle. It tilted the turbo away from the block and and aims the exhaust at a downward angle. To my knowledge no other CPL used that manifold and Cummins discontinued it due to the fact it seemed to cause premature bearing failure in the turbo. Those engines were commonly used in the Ford E350 vans. Below is a photo of one of those. You will find later produced engines with the regular rear drop manifold. Original injection pump on the engine is Cummins part 3908191. The shutdown solenoid listed is part 3903575 which is priced at $318.75. LOL. That's why most go with an aftermarket replacement. On the Bosch part number 0330001915 you listed, I think you may have one digit incorrect. The part number should be 0330001015 and here is one listed on Amazon for $19.43. https://www.amazon.com/Friday-Part-Solenoid-0330001015-1988-1993/dp/B073SP7QNQ They do come cheaper if they aren't in that pretty Cummins box.
Like Russ says, you just take your old solenoid and remove the little plunger and put the gutted unit back in the hole. Then get you a push/pull cable to connect to the little lever for operation. Tractor supply sells one for $16.99. Many diesel farm tractors had mechanical shut down. https://www.tractorsupply.com/tsc/p...8TIYYSOLYiZIdiXoeOpvKNOtQZn2LzFhoCIsQQAvD_BwE Or if you want cheaper Dorman part 55196 or 55201 are universal cables. Having your engine serial number you can go on Cummins Quick Serve online and see every part of your engine as it was made. Yours came just like the one in the photo I posted so it likely was in a Ford van. They were about the only ones that used that belt driven vacuum pump setup.