he may well have ideas of his own.but how about him making eg bird nest boxes,bird tables or similar which wouldnt need a large workshop--he could make a few samples and take them around retailers(pet shops,garden centres....)and come to an arrangement with the shops
Get him to help you around the house or do some gardening. Encourage him to learn computers, since that�s like the best way to keep someone occupied. You can probably get BigScreenLive.com software, which will help him learn faster. Many people usually find a lot to do with computers once they learn it. Try it.
Are there any 'Boys Clubs' in your area ?
Despite the horror stories about the 'yoof' of today, the vast majority of them are decent youngsters who may be really interested to learn some of the valuable skills which your husband can pass on.
There is a dearth of traditional skills and carpentry is certainly one of those.
He may just inspire someone to take up where he as left off.