Does anybody know what model of Milwaukee cash recorder this is. It appears to be a newer version of the 870 but I am not sure. In Jack's book, the 870 has the outside visiguage and this one has the internal sight glasses. Other than that it looks almost the same as the 870 with the exception of the pricer numbers and numbers for the total sale being on opposite sides. What kind of value would one put on it? Conventional wisdom would say this one is worth at least $300-$350 less than the 870 in the book because of the fact it has sight glasses instead of being a visiguage model but i didn't know if that would still be to high of a value or if this is a rarer model seldom seen. Are parts still available for this particular model? Any help would be greatly appreciated. Thanks.