5 Silver Arrows

Hi- OK, there were 5 Silver Arrows built. Placard at Blackhawk Museum (where one is located) says 3 are left; I thought 4 were left. Tom Derro (I think I spelled that right, apologies if not) has one he generously shares at meets. Where is the other one, or other ones? In a related topic, does anyone know which one spent time in the Houston Texas area during the 50’s or 60’s, I remember a picture of it in front of a store in that town, and heard rumors (when I lived in Louisiana) of it still being there. thanks David Coco