I may be able to help a little here as I currently own a few of these babies. If the parks don't have newer homes in it you will probably need to run it yourself. Believe me, these parks are a goldmine, but it is NOT money for nothing. You need to actively be involved in them. Most tenants that live in older trailers are are going to be one step above dealing with children for you. Their lives are almost always in turmoil....they are almost always broke, in the process of Divorce, in the middle of legal action and probably living off of the government. (There are exceptions to this rule but just remember what the nice lady told you about being tired and burnt out of it.) She didn't get that mindset because that park ran like a well oiled machine on its own.
But again, if managed and maintained properly, these little courts are a goldmine if bought with the right terms. Just a little insight from my experiences here.....when your young and hungry these are great because the money you can make more than offsets the headaches that you will have. But as soon as you gain experience through life's ups and downs and get to the point where money isn't a problem anymore, you will get tired of the police calling you at 3:00 am because some dude decided to beat the crap out of his wife and threw her out in the snow and the cops want you to come down and open the door for them so they don't have to kick it in. That's what can happen in a town of 5000 or less where everyone basically knows everyone. And that's one of the reasons you may want to live closer to the park. Plus the fact that older mobile homes take ALOT more maintenance than houses do.
If you get an obese person living in the unit, you will need to be good at repairing floors because the floors in them are pressed sawdust and a fat person will pretty much fall through wherever they step.
That being said, I would still buy it if it met your criteria, but please talk to someone that owns a small park first, they will know things you may not that will really help. I hope I didn't scare you off yet because the parks I own may be work intensive, but they are also part of the reason that I'm planning on retiring at 50. By then Ill probably be as ready to sell as your seller is. :) Contact me if you have questions, I'll help if i can.
Sean