Hi Kenneth,
Welcome to BP, lots of great people and information here.
I think your question is best answered by yourself, you say that the comps are from the 40's to the 80's, what does the 80's type properties look like? Better or similar then the one you are looking at?
If 80's is the most you can get, you are looking at over 80% of ARV if paying 68K for the property, if you add on Closing costs, landscaping, inspections, insurance, selling costs etc, I don't think you have a lot of room left for any profit.
You should first get some real comps from an agent that knows the area, then you need to factor in holding the property while finding a qualified buyer that can close, this could take up to 6 months if you are unlucky, do you have cash-reserves to support this?
It is good that you are out there doing things, it will only get easier the more you do. I would personally pass on this deal but I am also fairly new so maybe I am just waiting on this perfect deal to fall in my lap.
Good luck with your investing..
//Stefan