Intake - small letter “No Name” S1MS

[6s1640]

Hi all,

I picked up this intake years ago because of its uniqueness and similarities to a S1MS 1965 GT350 intake.  The nameplate is blank.  The temp sensor  provision is the smaller version.  There's no firing order nor part number . The  casting features for a PCV connection are absent and the casting sprue, typically with a manufactured marking,  has been trimmed off. There is a threaded hole in the very aft runner, No. 8.  What is the origin of this Intake?  Is it a prototype? Is it a test part to validate the casting? Is it an early production part?  Is it someone's creation by modifying a S1MS manifold?  It's a mystery to me. What do you think?
Thanks for looking
Cory