Can't say I've ever noticed one before (looks like it's located in the instrument cluster?) But the part number looks like 86640-10070 and isn't just for mk1 gt's. It's showing applicable for most Jdm ep82's on the epc. The only alarm bells I usually hear at 113mph are from my passengers..
Might still be available in Japan, you could try ordering via amayama
http://www.amayama.com/search?q=8664010070
Looks like $25 plus the shipping & associated charges.