Most REI should have access to one if you can't find a good one.

Lighting and security screen doors or access control for common areas; removing overgrowth that provides hiding places or pest havens; access area, curb, and hazard paint striping; these all add to curb appeal as well.

Could be this is very expensive or just plain can't be done.You'll also have to consider access, if just subdividing it results in land locked lots at the back.

Are there any restrictions?

Do you think the bank REO departments that were so hard to get in touch with may be a little more accessable?

There can be restrictions on the deed to make the housing affordable.

Chances are if someone is buying this rehab there inspector will find this, most people will insist this be fixed before they'll buy it and getting someone to fix a now chemical and sewage disaster it will cost double plus you may do finish work over the access point for the plumbing and that will have to be re fixed on top of a mess in your finished house.

If you do pay down the loan each month the equity is largely trapped so not easy to access if you really need it.John Corey

A few states have some specific laws that restrict or otherwise compromise what you can do with a lease/option deal.

Often you are restricted or limited in raising the rent each year (depending upon the funding of the program).