Much of the city is very block by block and its a good idea to take a look at the home values in different areas as well as the proportion of owning vs. renting in different sections of town. 

You can write them a letter showing that you are interested in buying the property. 

I am trying to find an offer letter template.

You can also request this information from the board as it's your right, but since they aren't responding, document it and report to the town. you can also provide proof of payment from your end as well and provide evidence you made the request and they haven't been responding. last option, get an attorney to send a letter and then lawsuit since their negligence is preventing you from refinancing and save money. 

We bought the house directly from the owners from a direct mail letter we sent.

Since that residence looks vacant it would make no sense sending out letter stating I would like to purchase the property.

I had to get 2 bids to build new from 2 contractors, I had just had it appraised, plus a realtor wrote a letter of valuation.

My cost of living is significantly lower than if I owned a house down the block; I'm even paying a lot less out-of-pocket than my tenants!

Once that’s done I want to hire a licensed contractor to apply for a block wall permit on wherever the property line ends up being located.I am hoping that I can do this before anything gets constructed.

If the County does have any old drawings in their records they may be able to share them; however, you will likely need to prove ownership or provide an approval letter from the current owners in order for them to release anything.