Islandtractor, believe me , it's dirtier now. It was so much fun to use that I never got off to take pictures. I'll try to get "proof of use" this weekend! I blame you for talking me into buying this! Any chance my wife won't notice this new appendage on the front of my tractor? I havn't pointed it out to her. If she does, I'm blaming it on you!
As far as the spacing, there are simply identical tines in the bottom between the big "teeth." They just don't extend forward past the round frame like the teeth do. The main bottom teeth are 9 inches apart and one 1/2" spacer between each. It certainly adds some strength to the bottom section, and keeps smaller rocks from falling out. Whether that is really important is debatable. I'll try to take more pix this weekend if this is not clear.
I doubt if this any longer or deeper that the stump grapple. I'll bet they have the same dimensions other than width. Why don't you ask Melissa at Markham? Also, these photos were with a wide angle lens, so there may be some distortion in scale. In person, it doesn't look so big. In fact, after I purchased it, my friend (who is a co-owner) commented it was smaller than expected.