To me, none of them make a difference in value because the original is gone….period.
If you to have to have something that looks the part, I’d go with a service replacement.
Me personally, I’d leave the transmission in there unless you feel that you have to change it, or if you found the original owner to that trans.
Kurt
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1969 SS396 Post Sedan Delivered to Van-T Topeka KS
MCACN Day2 Concourse Gold Award
1968 Schwinn Orange Krate Original Paint
1970 Schwinn 3-Speed Deluxe Original Paint