Pardon me for dumb questions but at 1026 Deere is approximately 25 hp. The grapple your building looks heavy enough for a 40+ hp machine. If I were building a grapple for my 4110 ( 21hp ) I would use 1 1/2 or 2" square tubing with an 1/8" wall. This is strong enough with a few gussets to withstand the abuse of the above machines. A 22' stick costs roughly 46 dollars. For $125. to include a scrap of sheet for the back plate the majority of the frame work would be complete. I would segment the grapple hooks with tubing and add 3/8" x 1 1/2" metal to the bottom side for additional strength at the welds and act as a contact for the brush / material your moving. The lazer cut pieces are top shelf in looks and durability but spendy for individuals like me who enjoy fabricating out of our steel surplus pile.
Like the thread indicates if your going to copy an existing design down to the lazer cut pieces your not gaining anything but welding experience. Fab shops have the equipment and get better material prices than single one time buyers. Many good comments and information exchanged.