I designed a felling bar some time ago with the intention of selling them etc, worked a little different than the conventional bars....but it ended up so big and HEAVY that that the cost of the shipping would have been more than the bar was worth. (see Attachments)
My previous experience as an accountant in the manufacturing world....that yellow felling bar would have to sell for about $250 before you would see any profit. And it would not do as much as a sledge and wedge in the woods...ask any timber cutter...they would probably laugh. One design suggestion/comment...too many welds.
One question....as you apply pressure does it have a locking mechanism? Say I get it up about 3" but a gust of wind comes long...do you have to hold it or does someone have to shove wedges in as you pry?
Now the felling bar that sherrill sells...I have had plenty of guys laugh and some ask me where i got it....
but after cutting a 60" stump and you have about 2" gap in your cuts this bar will pop it off pretty easily but maybe I put a little more into than most.