Thanks for the replies!
I considered the block and tackle, but did a bit of "back of the napkin" math and didn't like the answer.
My backstay is tensioned to about 1500 pounds. 6:1 tackle = 250 pounds pull, which means a winch
. This is doable, but annoying, and maybe a bit of grief getting it into or out of the cam cleat
I also looked at a multi-purchase system .. a 3:1 on the end of the 6:1, but the extra mount required just too many other problems and compromises. Plus, by the time a guy had bought suitable 18:1 hardware, he'd be close to the price of the "easy" solution anyway.
Mostly though, I'm just too chicken; in my head, standing rigging
has to be made out of metal. I know, I know, rope worked for a couple of thousand years and 20 years from now, SS rigging
will seem "quaint", but right now, 1x19 provides a certain comfort.
The comment about the threads does give me a bit of pause. I'm not worried about speed, I am absolutely a cruiser and not a racer. And the leverage can be overcome .. I'm a bit of an amateur machinist and so could easily fab up something suitable.
But the thread MATERIAL .. hmmm. All stainless would be fine, but I suspect mine are the typical plated brass and might very well start to wear.
Oh well, perhaps eBay it is!
Thanks again to all.