Well Tim, I'm not sure what a sliding sledge is......
but I met a man at a dig once that had a 2 1/2 - 3 foot long
and an inch or a little more in diameter iron bar with a chisel
on one end and a sliding weight enclosed in an area that
took up about the top 12 inches of the bar. You set the
chisel end where you wanted it and then just slid the weight
up and down to drive it in. It was beautifully made and the
perfect tool for working in tight quarters. I really wanted one.
Turns out the man made all his digging tools himself. I asked
how much he would charge to make one and he said it was
more a labor of love for him. Apparently he would search
out and use just the right iron/steel for the job. Materials
and labor he said it would be $150.00- $225.00, but he
wasn't that interested in getting into it.
The man lives in Kentucky and said the tool was perfect
for extracting Fluorite specimens from their limestone host.
Not sure if that's what you are referring to, but that's my
story and I'm sticking to it.
2011 Earthquake and Hurricane survivor,
Joe