A Raleigh built of Reynolds 501 tubing, there are oodles of versions of this bike and oodles in circulation. I have the Criterium version. Lightweight enough lugged frames that can take guards/rack and come in many sizes, mines about 25".
+1, good reliable entry-level frames these for trainers, winter bikes, commuters, light tourers etc. The Criterium is a cut above the other models not least 'cause it can accommodate 2 bottle cages for longer rides.
If you want to go a tad upmarket, try the Triathlon or Quadra which are 531 main triangle & fork blades. Although not designed as a tourer, my repainted Quadra (http://www.retrobike.co.uk/forum/viewtopic.php?t=213339
) with guards, rack & panniers fits the bill well and is a reliable, comfy ride - and a stable one too, even when laden with luggage.
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