There have been several questions about rolling stock weight lately, and we have the NMRA standards for that, but what about locomotives? Are there any weight standards for those? Specifically, I am speaking of GP30s, GP35s, and CF7s in HO scale. My HO P2K GP30 weighs about 17 ounces. My Athearn HO GP35 is 14 ounces. And the Athearn HO CF7 is only 11 ounces. It looks like there is room in the Athearn shells to add some more weight. Any thoughts or suggestions?