Originally Posted by sydney
^^^....There was also straignt gage tuesets in .91, .81, and .71mm Weight listed for he heaviest butted stuff in one reference was 2400 grams and the lightest 'SL' tubeset was 1800g.
I have a Reynolds tube order form from about 10 years back and there is no straight gauge 531 tubes listed. No doubt Reynolds will make what ever tubes a manufactuer desires (for a fee of course), but I can't help but think that straight gauge 531 is quite rare.