Model	Year	Serial Numbers
170	1948	18000 thru 18729
170A	1949 thru 1951	18730 thru 19400
170A	1949 thru 1951	19402 thru 20266
170B	1952 thru 1956	20267 thru 20999
170B	1952 thru 1956	25000 thru 27169
170B		609, 19401