Oil Rivers Overprint

Good morning, I found this stamp overprinted Oil Rivers, but it has an additional overprint haly penny in purple, but I can't classify it. Does anyone know if that type of overprint exists? Regards Simone

Check the relevant page on the website of the GB Overprints Society in below link.

https://gbos.org.uk/postal-agencies/oil-rivers/

Your basic stamp looks fake, It appears as if the (odd) blue colour is printed on the stamp and does not extend to the perforation tips.

Bottom perfs don't seem to match others. Reperfed?

The Oil Rivers overprint creates SG#4.

The "half penny" surcharge exists in eight types. If genuine, this one would be closest to Type 7, which does appear on SG#4, as a blue overprint, creating SG#22, and as a violet overprint, creating SG#24. (Also found in vermilion and carmine, but those couldn't apply.)

Catalogue values are in the stratosphere for both 22 and 24. Personally, I don't like this one, but don't take my word for it.

If anyone has a different interpretation, don't hesitate to pipe up.