I think I have a couple of used ones in my shed, I could sell you one, message me and I will give you my email address, I live in Vancouver WA across the river from you, so I am local.
My first question would be, have you had anyone that expressed any interest in your diesel lately, like did they ask if it was a diesel, have you noticed if someone else in your area that has a diesel, these are rare trucks, and stealing one takes knowing them unless you use a cable to start and shut down the engine, and then they would have to know that also, the steering does not unlock itself either.
Now that the question has been fully answered, I'll ask a semi-off-topic question:
How far off the ground is the front crossmember when the stock-length struts bottom?
How far off the ground is it when the shortened struts bottom?
I can't help but think that shortening the struts only lets the chassis hit the ground when bottomed. Is this mod for folks running tires more than 23" in diameter?
I Doubt this helps you track one down BUT this just popped up on my insta feed and I instantly thought of your post:
Attached is the high-res version and it looks like he has the same mirrors but using them as fender mirrors -
maybe my google-fu will help?
* $140 for Genuine 510 fender mirrors that looks super close to yours from what I can tell: https://www.ebay.com/itm/143380122887
* Zcardepot repop for $25: https://zcardepot.com/collections/mirrors/products/mirror-exterior-chrome-right-left-240z-260z-280z-280zx-70-83
The center-type will be just as good/bad as an improper-width conventional rack conversion. Doing all you can to get the tie rods parallel-ish with the suspension arms will help to minimize bump steer. Yes, both angle and different lengths will affect bump steer. The more travel, the greater the bump steer.
As mentioned, measure the total travel of the new rack and compare to the old box. It's possible that the rack has a slower ratio. but needs to be paired with shorter steering arms in order to preserve a quicker feel. Shortening your current steering arms may be too much of a hassle. It might be easier to adapt a box from another vehicle, like some other solid-axle truck.