Dinner theater progress can be measured in pounds and inches, in which respects the Lazy Susan, in Woodbridge, Va., is measurably improving. To its lavish Pennsylvania Dutch "Groaning Board," Lazy Susan appends "Oliver!" for cheerful holiday run, featuring a capable Fagin by Joseph Mullin.

Until the current "Evita," the London hit I've not yet seen, "Oliver!" has been the most successful British musical since Noel Coward's prime. Lionel Bart served as librettist, lyricist and composer for this adaptation of Dickens' "Oliver Twist." It became a popular film after three years on U.S. stages.

Bart's tunes are the major virtue, with "As Long As He Needs Me" a strong ballad linked with such melodic and lilting numbers as "Food, Glorious Food," "Where is Love?," "Consider Yourself," "It's a Fine Life" and "I'd Do Anything."

Though director Ronald Chambers seems to have elided portions of Bart's book and to have turned "Consider Yourself" into a street number rather than a welcome to Oliver from Fagin's little toughs, one always can go back to Dickens for why some incidents happen. As in the film, one misses Sean Kenny's stark, striking original set, a valuable counter-part to the sentimental, cheery songs.

Mullin's Fagin is a step up for this young singer who has been learning the acting craft in local dinner theaters for several years. Though nicely sung, his early acting in "Camelot," "The Boy Friend" and "Cabaret" was, to put it kindly, most woodenly conveyed. Here is proof that experience, intelligently used, can lead to skill. As Fagin, Mullin's acting is commendable.

Laurette Hankins does nicely by "As Long As He Needs Me" and Paul M. Luksch is an able Bill Sikes. Michael Patton and Mark Farinas alternate with Michael Kilarr and John Long as Oliver and The Artful Dodger, and Diane Jackson, a hearty lady with a hearty voice, is a capable performer indeed.

Performances are Tuesday through Sunday evenings.