Keeping my eyes out for a 1753 Ducat or Spanish or Portuguese colonial gold, then I'm complete 1723-1951. 1721 will be French colonial 9 deniers, and that's the last one that I can fill with something categorized as a colonial. Earlier pieces will include a Lion dollar, a 1663 British something, as that was first year without hammered coins (a guinea would be nice, but quite expensive), a cob, and other stuff I can drum up. The plan (at least in my spreadsheet) is to eventually go back to 1567, which is the first prime number year after the establishment of St. Augustine. 1607 will probably be a sixpence, as dated ones are available and it's the year of the establishment of Jamestown. We'll see how this works out, as I haven't extensively researched what's possible. The only pre-1723 coin I have for this set is a 1697 sixpence in PCGS 64.