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The placement here would denote either a C flat/ or a E flat

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Here is a common B flat signature:

https://www.liveabout.com/key-signatures-with-flats-2701101

Here are the Common clefs and their signatures:

https://upload.wikimedia.org/wikipedia/commons/7/73/Clef_Diagram.png

Here is an explanation of the Tenor Clef:

https://makingmusicmag.com/explanation-clefs-treble-bass-alto-tenor/

Because the only portion of the Clef that is Visible is the two dots on the E and G lines, It should be assumed that the marker is a BASE Clef.

Here are all possible clef notations:

https://www.musicnotes.com/now/tips/a-complete-guide-to-musical-clefs-what-are-they-and-how-to-use-them/

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You are correct that the Note transcription could include a♭Flat marker, on the E line, but I chose to Exclude it, for the sake of Clarity.