Hello Barry, welcome.
Do a search on this forum for 'water coil' or hot water coil. Or variations of that.
There are a lot of guys on here that heat their hot water with a SS coil in their coal stove. BUT I have no idea if one will work with a FrancoBelge stove. Most of the coils are made for a stove like a Harman, Keystoker, Reading, Hitzer, Alaska, Leisureline etc . These stoves have a single thickness outside wall that is 3/16" or 1/4" steel.
Take a look through the site, you will find lots of old and current threads on hot water for domestic use.
As fo the grate, I too think a good welding shop should fix you up. But there is a company that specializes in old stove parts, do a search on Google for coal stove parts, should find them. Prices may be steep though.
If the parts are in the hundreds of $, Keep an eye on 'papershop' and your local papers, you may find a good used Harman, Baker, Alaska or one of the many other stoves currently in production, so fixing them up is not such a problem. Often a good stove can be bought for less than $500.
Sit down grab a quart of your favorite beverage, and have a good 'read'.
Hope this helps.
Last edited by LsFarm
on Sat Oct 20, 2007 1:35 pm, edited 1 time in total.