Help with Riverside Ribbed EAPG Oil Lamp

Hi everyone. Today I have an EAPG oil lamp that I believe was made by the Riverside Glassworks. I find examples that show it as Ribbed Band #314.....Ribbed Band #157......etc. All examples I find show the base to reflect the same ribbed/band motif as the rest of the lamp. Mine has the same round base but without the matching pattern. Also, the 3 mold lines on the base/stem are no where near close to lining up with the 3 on the body of the lamp itself, meaning I believe they were made separately then joined without a wafer. I cannot locate any marks and/or patents/dates. I'm hoping someone here has more knowledge of this type oil lamp than I do and is willing to help me with maker/year/pattern...etc. Thanks again everyone. Stay safe :)

P.S. I believe it to be circa 1882-86