Go North, Young Man! It'll take a big pinata , but about 10,000 of you are invited to a very exclusive Memorial Day fiesta. Local historical groups are seeking descendants of the "Founding 44"--the 22 adults and 22 children who migrated from Mexico to colonize Los Angeles in 1781--for a weekend of campfires, picnics and Latino-heritage celebration at Griffith Park. Those 44 Mexican, Spanish, Indian and mixed-race settlers produced thousands of descendants; some of them don't know their heritage, some don't care--and some refuse to be recognized. Marie E. Northrop, whose husband is doubly descended from the pioneers, says that a staid and starchy Anglo lady recently "went to her deathbed" refusing to acknowledge her descent from a mixed-race member of the party. But others are proud of the forebears who braved the rigors of desert travel and a smallpox epidemic to get here. "It was rather difficult to get volunteers to come up here because it was risky. They never knew what they'd be getting into," Northrop says. Newcomers still stream into California, and today's migrants, who choose to stay even after getting a good look at Hollywood Boulevard, are probably just as brave. Ars Gratia Caddie When Walt Stewart slides behind his steering wheel, he silently blesses a cramped Los Angeles courtroom and John Z. DeLorean. Every day of the four months that DeLorean spent on trial in the courtroom, Stewart was there, too, drawing overtime as NBC-TV's courtroom artist. DeLorean was acquitted, and Stewart, with his overtime, deserted an aging Chevy and bought his dream car: a 1976 "amber-glow fire mist"--in other words, drop-dead red--Cadillac Eldorado convertible, with seats as white as, well, snow. To show his gratitude to the man who made it possible, Stewart ordered personalized plates: THX JZD. Stewart and DeLorean, both now freed from California courtrooms, recently ran into each other, and Stewart showed his dreamboat to his benefactor. Says Stewart of the Silver Shadow's reaction: "He thought it was funny." No telling the thoughts of Folsom Prison inmates who hammer out the plates. Tress for Success Francisco Goya's "Maja" was inspired by an undraped duchess of his rather intimate acquaintance. Dorothy Taylor's creation was inspired by an RTD passenger she never met. After years of doing gewgaw handiwork-- mostly on the bus on the way to work--Taylor was at a bus stop in South Central Los Angeles when she saw that hair: elaborate, gold-beaded corn-row braids. Within a few weeks, Taylor had abandoned quilts and Christmas angels for Beadi Babies, black dolls with jeweled yarn coiffures. She's shown them at doll exhibits and sold some through the Afro-American Museum of History and Culture in Exposition Park. Her most ardent fans, though, are at A-Dopt, a private adoption agency whose psychotherapist, Patsy Hankins, has made a point of giving Beadi Babies to the children she handles, like the 9-year-old black girl recently placed in a white foster home--"a good transition for her to take along something that looked like her." A-Dopt's Northern California office gives Asian-type Beadi Babies to Indochinese children here for adoption. "When a child steps off an airplane from a foreign country, for them to have a doll that looks like them--it's great." Caveat creator: Taylor has raided her own jewelry box for Beadi Baby adornment and has Robin Hood designs on yours. "You're in danger if you're wearing something pretty and I have a pair of scissors."