I wouldn't think there would be Pt's for a <600V service - at least I have never seen it, but hv&lv knows more than me on that stuff, could be some that do it with PTs.
One way you can find out the multiplier is if the meter gives you an instantaneous kw figure and you can clamp the service somewhere. But probably best to call power company, I agree with others that that value - you won't really know what time period it is anyway and probably not usable for NEC purposes.
I actually just got some data from SCL for two meters yesterday and they sent it without requiring owner's authorization, they sent me daily demand for a year it was pretty sweet.