2.3% Rule; and BRRRR 17 yrs smoke damage

[Account Closed]

I set a goal about 6 months ago that I would make my first purchase in Q1 '17, and I'm well on my way. I found a property where the owner is looking to get out of rentals. He's owned the property since ~1970, but looks like a fairly good investment My biggest trouble is finding comps, so estimating ARV is difficult. I even went back in sale records for 3 years! Here are the details on the property

Janesville, WI

4 unit; 1b/1b each

Asking Price: $100k (Also assessed at 100k)

Rent: $2300 total

Landlord Costs (Gas, Water, lawn/snow): $303

PITI: $832 (after Refi with loan value 98k)

Vac, Maint, CapEx, Mgmt: (8,10,8,8) $782

Repairs: 17 yrs SMOKE DAMAGE; new roof; new windows; Kitchen updating - Estimated: $25k

My only comp is another seller with 4 unit; 3 units with 1 bed, 1 bath; 1 efficiency; who said they were putting on market for $160k (though assessed at $115k). Trying to be conservative, I estimated my ARV at $140, but I'm wondering:

Can anyone suggest other data points I can use to estimate ARV?