NBC reportedly is mulling a Friday mystery movie wheel as an option for next fall’s schedule, with “Perry Mason” telefilms and a possible revival of the early ’80s series “Hart to Hart” among the potential spokes.Sources say there are talks with stars Robert Wagner and Stefanie Powers about “Hart,” which ran originally on ABC from 1979-84. In addition, a commitment to singer-actor Kenny Rogers on an hour series could be converted into movies as a third wheel component. NBC reportedly has ordered another half-dozen “Perry Mason” movies for next season from producers Dean Hargrove and Fred Silverman and Viacom Prods. The “Mason” vidpix have been running off-and-on as part of the Friday lineup since October, when the network canceled “The Round Table” and two short-lived reality shows. A network spokeswoman stressed that nothing has been set regarding a wheel on the schedule or deals with Wagner and Rogers. Whether the wheel rolls onward apparently will be contingent on several factors, among them how the web views its development. Observers note that one of the major attractions of another movie slot is that it takes care of two hours on a given night and allows a network to focus attention on other areas, as CBS did with its Saturday movie last season. In addition, the combination of ABC’s “TGIF” comedies, CBS’ slightly older-skewing comedy block and Fox Broadcasting Co.’s reality hour “America’s Most Wanted” have made it difficult for NBC to establish series on Friday, though the network has performed reasonably well (albeit primarily among older viewers) with “Perry Mason” and other movies. Such made-for-TV movie slots have routinely been used by networks on nights where they’re having trouble. Most recently, ABC offered a “Saturday Mystery Movie” (composed of such rotating elements as “Columbo,”"B.L. Stryker” and “Christine Cromwell”) in fall 1989. Series bloodlines “Hart to Hart” was created by novelist Sidney Sheldon and produced originally by Wagner’s company, Aaron Spelling and Leonard Goldberg in association with Columbia Pictures TV. James Veres, who has an overall deal at Columbia, has been mentioned as a possible producer on the movies should a deal be reached.