Old Car and Bike rambling

I wanted to replace my original speedometer and tachometer for something more compact. I'm not sure why, but the original 85mph speedometer always bothered me. I guess I felt like the bike deserved better even though I've only pinned it once in 10 years of riding.   After casually looking around and almost pulling the trigger on a cheaper universal speedo with an analog sweep needle for the tach, I stumbled across this product. It can be found in all the usual places such as Amazon and eBay but it's usually buried behind 2 or 3 pages of search results with vastly different prices ranging from mid 40s to mid 80s (US$). The description typically includes a listing of what each wire is intended to be connected to, but in typical fashion for these kinds of imported products the English translation leaves a lot to be desired. For example: the product detail notes: "Oil Quantity Indicator" as one of the display areas, but they really mean fuel level (my bike doesn't