You can definitely modify this to fit the space you need. We bought 1x4 pine and 1/8" masonite, it was the same thing the peg boards are made from only without the holes...I am pretty sure it's called masonite anyway. Decide how many rows wide x how many columns and multiply this for your total in compartments. We cut the masonite into 4 1/8 x 3 1/4" squares (one for each compartment minus however many columns wide you are making it. You cut the 1x4 the same number of inches as the rows you decided on, and you cut one more than the # of columns. Mine is 4 columns of 13 rows...so we cut 5 1x4s at 13 inches long. We ripped these down to 3.25" wide, and then routed them with the table saw blade at every inch slightly over 1/8" deep. All but two get routed on both sides, and the last two just one side (these are the outsides). Then we fit all the little shelves in (pound with a rubber mallet...it's a tight fit) squared it off and air-nailed a full-width 1x4 cut with a slight overhang to the top and bottom. We added a square of masonite to the back too.
I am trying to get DH to help with a new one as I recently ran out of space! So make it BIG enough the first time!