Oil galley plug

[sr vegas 240]

So i had my block fully assembled and i find an extra oil galley plug. Have no idea where it came from. I contacted mazworx they told me there was noting on the inside of the engine. I just have no clue how i got an extra oil galley plug.

intake side
https://preview.ibb.co/guNj4q/20181119-113651.jpg (https://ibb.co/cR2j4q)

exhaust side
https://preview.ibb.co/jibBjq/20181119-113723.jpg (https://ibb.co/nf4LcA)
https://preview.ibb.co/gsWBjq/20181119-113713.jpg (https://ibb.co/hQ7j4q)

back of the block
https://preview.ibb.co/jDCOxA/20181119-113656.jpg (https://ibb.co/jMvMjq)
https://preview.ibb.co/fhv44q/20181119-113700.jpg (https://ibb.co/jwYrjq)

timing area
https://preview.ibb.co/duP3xA/20181119-113708.jpg (https://ibb.co/iRBSPq)

here is where it gets confusing somehow i have a new plug i did not buy it, unless it came with some other part which i do not remember, maybe the acl oil pump no clue.
https://preview.ibb.co/eCK6jq/ASLDJF.jpg (https://ibb.co/bVHsPq)

Can anyone verify there is no other plug on the inside of the block/head or something i'm missing.