Just took delivery of my new L3901 and wonder how I ever survived without it (my RTV500 has been pushed way beyond its intended service). Like everyone else I found the OE toolbox good for not much more than storing a grease rag. I had several plastic ammo boxes, one which is orange, and repurposed it for behind the seat storage in place of the OE box (can't remember where I bought it). It's about 6"x14"x10", and is big enough to hold 2 sets of sockets and end wrenches, a set of pliers, screw driver, rags, and couple other items. For reinforcement, I mounted the box on a 1/2" PVC plate, put a 1/4" PVC plate inside and used fender washers and longer screws to mount to the bracket's welded-on nuts. Since there's never enough storage, I added 2 steel 50 cal. ammo boxes to the FEL L/H tower, as many other owners have. My "saddlebag" mounting method is a bit different as the attached photos show. I used 2 scrap pieces of Trex decking (7/8" thick is perfect) to space each box away from the tower so the lids clear the pivot pin flanges and to reinforce the wall of the box. I used four hex head 3/8" x 2-1/2" bolts to mount each box and located the bolts in a pattern such that bolt shanks rest on the tapered tower, and thus define the boxes' vertical position. The bolt pattern on the boxes are mirror images so that each bolt pair meets at the center and is joined with rod couplers (about 1-3/4" long). The bolts are snugged so that the assembly stays in place. Jam nuts on each bolt are tightened against the couplers so that everything stays secure. The bolts have 1-1/2" fender washers on the box interior. This mounting method avoids making any modification to the FEL tower, and the boxes can be removed easily in about 5 minutes. I could have used 4 long bolts (about 6") to run all the way between the boxes, but I wanted to minimize obstruction inside the boxes (nuts, lock washers and bolt ends). A single box can be mounted using the same technique. My tow chain, lunch and drinks now have a home. Maybe I'll paint the boxes orange when I get tired of driving the tractor.