Tam's Model A Parts. A3000GG ~ Grease Gun Adapter U.S.A. 1928-31
American Forge & Foundry Right-Angle Grease Coupler with Polyurethane Seal, for Hand-Operated Grease Guns Only in the Grease Gun Parts & Accessories department at Lowes.com
1/4-28 Male x 1/8 FPT Straight Grease Fitting Adapter - Kimball Midwest