I was rather short of ventilators for the roof of the MHO and in keeping with the minimum cost idea of this O gauge layout I searched around the house for something suitable.
After ceasing to be part of the music scene some years ago I had stored away a large collection of guitar strings which I discovered recently had rusted away quite nicely ( note for next life.... store them in oil). After inserting a suitable nail in one of the brass turnings that are attached at one end of each string I decided this would do to represent a mushroom ventilator.
And so it came to pass that the MHO was ventilated.
Santa heard my plea and arrived early with some wireless upgrades to my Digitrax UT4's and a duplex radio interface. Bliss!!