I have confirmed (without a doubt) that Lark Records was a Detroit label that was connected under the umbrella of Detroit's Sound, Inc. Production company. Brothers, Danny and Larry Lick (Pavelik), and their cousin, country/rockabilly singer, Johnny Powers (Pavelik), (all Detroiters) owned it. Ernest Kelly may have been involved at some time). It was located Northeast of Detroit. Sound Incorporated had more than 20 labels affiliated to it, including: Sound, Universal Sound. Sound City, Velgo, Lark, Thump, Sidra, W.I.G., Amon, Poo Pan, Drifter, Walker, Cupid, Keepsake, Lusty, Monee, Radio, Oceanside, Fink and Trash Records. It had it's own rcording studio and pressing plant.
Here is a link to a thread we had on Soulful Detroit Forum some years ago, in which the owners Detroit's Pavelik Brothers, including Johnny Powers, and their headquarters' address (in the Greater Detroit Area), and listing all the labels involved:
https://faac.us/adf/m...html?1237305322
The SI pressing number series is the same as all the other Sound, Inc. -related labels use (as I stated above), they had their own pressing plant.