"...I am also told that it was bought new for around £200. That amount in 1938 apparently can be equated with almost £10,000 today (source: http://www.measuringworth.com/ukcompare/). That seems an awful lot so I'm not sure how accurate the £200 figure is..."

I just received a copy of a sheet of want-ads from USAZorro yesterday, that show in 1949 a typical bike was selling for about £20 at the top end. I suppose all things are possible, but I'd guess that we have an additional zero added by retelling or something.