Some really worthwhile contributions here, and I thank you all. I'm getting in a bit of a pickle over this and thinking about it when I ought to be trying to get some sleep, so other people's views are very helpful. Trying to take some of the points above:
I think the drop bars on the Dawes are the main issue. I rode drop bar bikes from the age of 14 to about 35, but since then 99% of my riding has been on an MTB. I don't find the drops very comfy and I prefer a more upright riding position these days. Other than the position (and those levers) the bike is superb. The frame is superbly comfy. I guess the question is simply - is it better to fit flat bars/bar ends and thumb shifters to the Dawes (most of which I could offset by selling the Sora STIs), and end up with a knit-your-own hybrid, or cut my losses, sell the Dawes and start again - this time knowing much more about what I want. (I think the Dawes was a bit of an impulse buy, to be honest. Most of my riding is poor-quality back roads, and the Dawes, even though it seems quite rugged and a touring bike, seems a bit too 'roady' for that.)
The spec for the ideal bike would be: steel rigid frame, flat bars/bar ends, triple chainset with good low range of gears, thumb shifters, disc brakes, 26" wheels. All doable, except for the brakes, but I think it would be better to move the bike on to someone who wanted a dedicated tourer, and use the Raleigh until I can sort out a bike that is closer to my needs. A swap would be ideal, of course, but would need a dose of luck. I think I will get rid of the Dawes by whatever means and start again, but probably in the Spring. I will definitely pop back to my LBS to see if they would do a buy-back or part-exchange, and perhaps put a post on here to see if anyone is interested in a sale or swap - otherwise, put it back in the garage and wait until the warmer weather returns.
I've been chewing this over for weeks, and the opinions here have really helped me focus on the important things, so thanks to everyone.
