Serial # question 860

I looked up the serial number and mine has one to many digets according to the list on yt's serial number guide.
My number is preceeded and followed by a diamond mark, the number reads 1361185.
Can anyone help me with the year and why I have a 7 diget number?
Thanks
Bill Price

Is your 860 a propane model? That's what the "L" would indicate. As for age, there are some date codes here and there that might help. Sometimes there are date codes on the forward facing surface of the rear axles. The codes I am familiar with start with a letter followed by 2 or 3 digits. The letter calls out the month (A=Jan, B=Feb, etc), the last digit calls out the year (5=1955, 6=1956). Whatever is in between is the day of the month. My axles are G255 (July 25, 1955) and G225 (July 22, 1955). On gas models there is usually a date code on the brass tag of the carb. I don't know about propane models. Another place to look is the top of the radiator. Stamped in the metal close to the filler neck should be a date code such as "6 55".