Here are the two variations of the Senaca Lodge #394 S7. Only the S7b had been previously pictured on OA Images. Thinking of these as twill backgrounds, the stitching in the background goes from lower left to upper right in the S7a. The b variation appears to be stacked in vertical columns.
The images are displayed below.
 The Blue Book describes them as:
S7a BLK R WHT BLK WHT FDL; HOR bkgd patterns DIAG right
S7b BLK R WHT BLK WHT FDL; HOR bkgd patterns VER rows