Columbus Day weekend discovered new coin on the Rialto, with total Broadway grosses up $1.7 million to just over $16 million for 25 shows on the boards.The first holiday weekend in October is considered by many legiters a bellwether of fall sales to come, and this year’s tallies are encouraging. Cume is up about $70,000 from 2006 receipts of the same week, and attendance (slightly more than 203,000) is about equal — all that with one fewer show running now than last year at this time. Biggest jump of the sesh was seen by “Hairspray” ($802,312), which added $170,000 in extra volume, while “Legally Blonde” ($793,882) and “The Lion King” ($1,171,460) each climbed around $150,000. “The Color Purple” ($872,163) and “Rent” ($454,535) also ascended well over $100,000 each. In general, the overwhelming majority of productions stepped it up a notch, most at least by sizeable five-figure bumps. The only real dip of the week came from “Xanadu,” sliding by a bit more than $30,000 to $240,772. Among recent play additions to the Broadway slate, “Mauritius” ($193,985) experienced a modest rise in its opening week. Previewing Roundabout offerings “The Ritz” ($292,611) and “Pygmalion” ($287,429) also upticked a bit. The one new addition for the week was Chazz Palminteri’s turn in his own solo show, “A Bronx Tale” ($146,469), which played four preview perfs to auds of around 70% capacity.