When i first fired up my 58 that had been sitting for about 30 years, the fuel pump shot gas EVERYWHERE. I pulled it off and just slapped a new one on there, if you want to keep your original pump i know chevs of the 40's has rebuild kits. As for the arm wiggling or not..it shouldnt wiggle, there should be a significant amount of force needed to push the lever in or else i don't think your goign to get any fuel pressure.
