This penny has the left edge thicker & the right edge, the date & mint mark fainter. Is this a commonplace occurence or something I should hold on to?
If the coin is off center on one side and not the other it’s called a misalignment strike. If it’s off on both sides it’s an off center strike. Ether type of machine errors is pretty common and worth no more than face value. It’s not till you find them with more than 6% off and start to miss some of the detail and fields when they become worth something. The weak date could be from over polished dies, a weak strike or a bit of grease.