My Caddy sat in a lady's back yard for 10 years with old gas in it, so I feel you there.
I struggled as well, but was able to resuscitate it using all the original parts, including the injectors (and the cold start inj.), lines, WUR, fuel distributor and air box/flap. I cleaned everything with carb spray and compressed air, and the only thing that needed replaced was the pump and filter. After doing all that work, my 1.8 actually runs too rich and needs to be adjusted.
On a side note, I just found my original fuel distributor, which I rebuilt, so that will be changing it out soon.
So I guess what I'm saying is you can probably get that CIS-Basic to work. But I know the struggle, so a swap would be cool to see

One of the differences between CIS-Basic and Lambda is the O2 sensor...can you swap over the exhaust from the Cab, or do you have a plan to run or delete the O2 sensor? I've wondered what others have done, but never asked.