No problem. When you make unverified statements, I will continue to correct.
In this thread, you state that 3/8" is correct. That was my first answer. After I corrected it to point out that 3/16" is the factory spacer and posted the copy of the parts manual, you decided that 1/2" was correct as well. Then you gave a Part number 1560480 for the 1/2" spacer. I stated that 1560480 is not listed in the parts manual. Your justification is that SI lists it.
Even if we accept your reinterpretation of the question, the complete answer is that 3/16", 3/8" and 1/2" spring spacers were available from Studebaker. 3/8" and 1/2" are specified service only meaning they were not installed at the factory.