Ouch!
All that leaded glass....
I don't think I'd be able to give a price to be honest, if they want that work done then be up front and charge them a day rate.
Initial cleaning leaded windows is no joke.
I'd avoid it like the plague if it was me, and I'd not like to tell a customer just how much I'd have to charge for a day rate.
For me, being all WFP, I tell customers that I no longer work off ladders (and yes..I use that as an excuse!)
You're welcome to that one!
Ian