I have always loved tinkering with various bits and pieces and I love this site:
The Museum of RetroTechnology
I have little doubt that one or two resourceful people on an airliner could make good use of its resources to cobble together quite a few things mentioned on this site. Have a look, and I hope you might find something useful to your story!
As for the ditching/landing, there is the precedent of the BA 777 which crash landed at Heathrow after engine icing problems shut them down.