Didier, were the handles carved into a different shape?
No, only some sand paper and after several times : linen oil with turpentine on the wood handle (like a shotgun in europe). You will have a better grip.
I think that if you shape the handle it will be less versatile to dig or to cut. This tool is very simple, this is the great advantage : simple to use (with frozen hand, in the dark...) and to repair, truly a war tool.
Just shape with sand paper the part of the handle who is near the beginning of the "steel hole of the blade". When shovel come from CS you have a difference in diameter with the steel part and the wooden handle. Better to have a smooth frontier between wood and steel, so your hand could feel nice everywhere.
The end of the part of the handle inserted deeply in the steel blade could be slightly "flutted" : so it is easier to dig.
The sheath is used with a five feet rope (approximately). One side hold the sheath and with the other side of the rope you make a loop and you could catch the handle with it. So you could have your tool across your back and it is easy to use it.
A shovel on my thigh will not be very pleasant. Our shovel in army are like WWII US : the handle cling on your leg every time (noisy, hurt you...). Better to bring it on your rucksack or across your back with a rope.
Not sure to explain well in english. If you could not understand my english...ask me : I will try to do better.
didier.