Hi Gabe,

Thank you for contacting Mearto with your appraisal inquiry.
Most of the Delco signs on the market are advertisements for their batteries, so this is a comparatively rare example as it's just for their oil. However, the fact that this missing one fairly large section - which features a great graphic - negatively impacts its value.
Based on the photos and information provided, and subject to examination, this is:

A vintage Delco Motor Oil coated tin advertising sign
made by Lindsay McMillan Co, Milwaukee, Wisconsin, circa 1930s-40s
The rectangular sign in black with yellow and white lettering, lacking the lower left corner in which was a bold figural graphic.
27 inches high by 40 inches wide
CONDITION: in poor condition with a split across the lower register and one corner missing.
$800-1,200*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, and thank you again for using Mearto.

For an idea of what this sign would have originally looked like, look at the reproduction at this link:

https://www.etsy.com/listing/1254799523/antique-reproduction-vintage-style-steel?gpla=1&gao=1&&utm_source=google&utm_medium=cpc&utm_campaign=shopping_us_a-home_and_living-home_decor-wall_decor-wall_hangings-signs&utm_custom1=_k_Cj0KCQjwyOuYBhCGARIsAIdGQRPsOI5KcrgCfHJsFwc97ivKcfD5BVEDy-fjufe_2O449JcETqGb9nwaAvlyEALw_wcB_k_&utm_content=go_12574416432_120844879578_507798881904_pla-305562556246_c__1254799523_129322999&utm_custom2=12574416432&gclid=Cj0KCQjwyOuYBhCGARIsAIdGQRPsOI5KcrgCfHJsFwc97ivKcfD5BVEDy-fjufe_2O449JcETqGb9nwaAvlyEALw_wcB