Chainsaw Repair

Hello I have a chainsaw that looks exactly like the one that W8ye posted, but the sticker on the clutch cover has worn off and I can not identify the chainsaw. The plate on the back of the handle says type iii with a seriel number. I called poulan and they said none of the numbers where the model number and they were t able to identify it by the numbers I am there are two different numbers on the sticker on under the type iii says its the seriel number and the a number that starts with a 97 which I am assuming is the manufacturer year.  I looked around the forum I figured it's either a 3300, 3400, or 3500. How do I find out and what's the difference between those three models? Thanks in advance.

William