I too post very frequently on the CCRS site (in my opinion, the best going for up-to-date info) and only infrequently drop in here to see what's going on. Vicky large cents and all their varieties are my specialty and I have over 3000 with nearly 500 1859's. The other posts from Bosox and others are right on. The minting process and alloy percentages in the planchets was not exact for the Provincial cents. 99+% of the 59's that look a little yelllow are just those that have had a harsh chemical exposure, intended or unintended. Most (and I say just most) planchets that are oversized are foreign copies. They were originally made to be 1 inch in dia (25.4 mm) and 100 weighed a pound when new .. by design. Those with wear will always be a little shy on the weight.