+1 to littlesmokey
I didnt even read one reply but as soon as I saw the pictures I knew I was about to witness a virtual beating.
Its like having a 'beater' car. Some folks would never dream of having a beater, or be caught dead in one. The beater may guzzle gas, cost lots of maintenance, etc etc. But when you can't even afford the cost of a shiny new piece, well you dont have a whole lot of choice, even if in the long run the beater costs you more. I know lots of folks who have old stoves, fishers, VC's, inserts w/o liners etc and they all work fine, folks are happy with thier heat output, wood consumption, etc etc. Sure there will always be a better unit out there, more efficient, nicer looking, whatever. As a matter of fact besides '1' stove, I know of no one that has an epa stove. Everyone I know that burns wood uses older pre-epa stoves (and inserts) except 1. My BIL wanted to give me an old insert sitting in his garage, maybe from the 70's? He was rather offended and couldnt understand why I shelled out over $2k for a new one when I could have had his for free. And to be honest it was a large part due to looks. I think my new one looks great and runs great, but I dont consider it all that great of a heater to be honest, and my old pre epa stoves just blasts it away with heat output, but it is much larger and freestanding.
I can't offer much advice though, wish I was more of an expert but can;t say that I am. But I can say that in your situation, your going to have a bit of a struggle to accomplish what you hope. It is an old unit, no way to deny it, and not designed for a liner. Its designed to just be sealed up to the fireplace, which as far as I am aware, is against code to do (although I do know multiple folks personally who have inserts exhausting directly with no liner hooked up). In some areas you may be able to run a partial liner (unlike the previous responder who said all liners always go to the top - false) but even if your area codes and insurance company would allow such a configuration realize it is still less than ideal, still wont draft as good as a full liner, and makes it a pita to clean. Then there is the question of the liner size, and if 6" will even work well. For a 'block off plate' do a search for that term here on the forum there are tons of threads about them(I had one a little while back) but the problem is each one is unique and you have to improvise if yours is a bit different.
Do you have a free source of wood? I mean are you going to cut it yourself or pay for it delivered to you? If your trying to save money, sometimes wood does not - something else to realize. What other source of heat do you have (oil? propane?) sorry if I missed you saying this already. The main issue with trying to save money by burning wood is that to get a nice efficient unit setup properly is a big investment. But if your burning oil or propane it will for sure save you money in the long run. For example spending $3000 or more on a new stove might seem like a lot of fuel, but I'd spend that much in one winter alone. Now if you have an efficient natural gas furnace and you have to pay for wood, your really not going to save much.