Thanks Tom and et all... we have a straight run.. other than I built the stairs with "the suggestion" that they turn over the last 5 steps by making tapered treads so that you would get the illusion you need to turn as you exit the bottom of the stairs. Works great, but it does make for a small concave shape to the stair rise overall. Shouldn't be an issue, I'll just have to modify the center support legs or shim the ones that come with the lift. Screwing into my nice oak stairs isn't high on my want to do's.. but what can you do.
Dan B has me all set if I need him, with a generous offer to supply and install. I also have a lightly used one lined up that has the 17' track that I need. Dan says adding a bit isn't generally possible as they normally get sold as 16' units and get cut down for shorter rises. IE: they're designed for one mid span joint using two 8 foot tracks.. not a 2nd joint to add a bit to them with the rack and pinion gear having to mess perfectly.
Hoping Leah gets a chance to talk with the other girls mother soon. Either way I may just go snap up the used one I found as I can always resell it if I don't, and hopefully don't, install one.