New Here and Having issues buying an 87 silverado

[chevymotocross]

I have been looking for a clean 81-87 silverado 2wd swb for a couple months now. It's hard finding anything decent in Connecticut or surrounding states. I found a pretty clean 87 silverado 10 min from my house a week ago. It's the color I like (black), has very minimal rust, strong running fuel injected 350, the 700r4, cold a/c, and all the silverado options in working conditions. Test drove the truck and it ran/drove great. I got the seller down to $2500. Gave him a refundable deposit to hold it. This truck is at a small used car dealership/repair shop, and the owner of the business is actually selling it for someone he knows, it's not his truck, he is doing someone a favor. The truck is still registered and plated with connecticut plates. I call him up and ask who to make the Bank Check out to. He says CASH ONLY. Ok, so I ask if he will write and sign some type of receipt to prove of the cash I am giving him. His answer was no. The way he will do it is "give me title, bill of sale from the owner, keys to truck, I register it myself, if any problems registering, I get money back you have my word". I don't want someone's word when making a $2500 purchase, I want written proof. Here is the other issue, it's plated with CT plates.... it has a Florida title! Owner of the business claims the title is in his friend's mother's name who lives in Florida. What the heck, how does it have CT plates and registration sticker with a Florida title?! So I ask if he is unwilling to sign on paper that I am handing him $2500, if he, as the seller, register it for me, and I even offer to pay him for those services. He says no. How can I give someone $2500 cash, with no "receipt" no written signatures, without knowing it will register fine at the DMV? I am super dissapointed after finding the truck of my dreams literally 10 min away and now I can't buy it because of shady business. What you guys think? I am NOT going to pay for this unless I get a damn signature that I am purchasing from him. This way, if it doesn't register at the DMV, I have proof I bought it, and he will have to pay me back!