Need advice on purchase of a Johnson 50 HP and boat

I have been searching from some time for a cheap fishing boat and I think I finally found one. I am going to look at it after work today. From my internet searching it appears to have a 70's model 50 HP Johnson. Some of you might be able to tell more about the motor from the pictures below. The boat is an older man's boat that is selling it due to health problems. What I like most about this boat is it appears that it was his baby and he maintained it well. Also the trailer is newer and has bearing buddies on it. Sorry enough trying to convince myself. If this motor was well maintained is it a reliable model? Are parts still available for it? Is there any trouble spots I should look at when I go a see the boat? He is asking $800 for the boat. Do you think that is a good deal? This will be my first boat purchase. So if have any thoughts or comments please add them. Thanks for your help.