Hi CO levels found during inspection

[Dave Versch]

I'm under contract to purchase a 2 family house in Buffalo, NY. I had an inspector check the place out today, and he found CO levels so high in one of the units that he had to call the gas company to come and shut off the heat for that unit. This unit is heated by this ancient combination stove/furnace thing, which is the apparent cause. (The other unit has a separate furnace and uses forced air, and doesn't have a problem.)
I'm planning on insisting that the seller remedies this situation, but I'm wondering what the best resolution might be. My first thought was to suggest shutting the gas, capping it, and installing electric baseboard heat in that unit. Problems with that though are (1) the tenant's electric bill will go through the roof - it gets COLD in Buffalo, and (2) they'd probably have to purchase a new stove so they could still cook, so they'd still need gas. I don't mind if the seller purchases a new stove, but I'm sure if the electric bills go way up, the first bill the tenant will sacrifice will be my rent.
Any suggestions? Has anyone experienced a similar situation?