Jack Hammer Bit Heat Treating | Heat Treating | Forum

Junkyard Steel at Anvilfire cites Machinery's Handbook for info on unknown steels. Jackhammer bits are listed as 65 to 75 points of carbon in my 1943 edition (year of my birth!). Do the currently available bits likely still have the same carbon content?
I need to make a spacer ring for a fly press I am refurbishing to fill the gap resulting form machining off the fractured end of the screws’ 4 threads. Would a thick washer turned from the bolster part of a bit be a good steel choice; tough, wear resistant, and not too hard. I'm also thinking of adding a brass 0.005 shim stock washer for a replaceable wear surface between the new spacer ring and the sliding block (that called the bolster?). I'll experiment with the heat treating quench as recommended by the article on Junkyard Steels, then plan to temper at 500F. Comments or suggestions welcome.