You can get large (12") 24 hour clocks for about $25.00 from MFJ <http://www.mfjenterprises.com/> look at models 105C or 105D (cases are slightly different). You can get a 24 hour quartz movement and a 6" 24 hour dial from Kockit <http://www.klockit.com/> model 34089 to fit into a case you may have. If the 6" dial is the wrong size just copy/scan it and use your computer to shrink or enlarge to fit then print. Klockit makes a cheap
plastic wall clock kit #37487 which fits the 24 hour movement and face and comes in red, white, blue or black for around $8.00. I have made some for my grandkids.