I think they are the same tuners as the standard full size Casino. I recommend buying a cheap set of digital calipers and measuring the tuners you have and see if the measurements match the specs on Stew Macs site.
Stew Mac has some that should work. http://www.stewmac.com/Hardware_and_Parts/Tuning_Machines/Guitar_and_Solid_Peghead/Gotoh_Vintage-style_Oval_Knob_3and3_Tuners.html
there are also a set of Grovers that are the same style