Costumed performers and tour guides are fighting for unionization at the Lower East Side Tenement Museum, where they work to recreate the squalid living conditions of turn-of-the-century Jewish immigrants, the very group that was integral to 20th century unionization efforts. Dozens of the tenement employees protested last night outside a fundraiser for the museum at Chelsea Piers. Most of the guides work part time for an average $17 per hour, with no regular pay increases,......