Thank you very much for this. Let us hope this straightforward modification is taken up by many others in the Forum. It really is a major improvement.
Yesterday was the first day I had a chance to play my alto seriously since I got it back with the 8th string extension removed. It's fantastic. I have discovered several places in the pieces I play where I can play the bass note on the 7th string, but playing it on the 8th string is better (easier to damp). For example, in a situation where the basses go from low D to low B, by playing the D on the 8th string you avoid that skip in strings and the damp happens automatically. Much smoother.
I reckon the reason Georg Bolin designed the guitar having only strings 1-7 the same length is to make it possible to use a 6th string for all the basses. When you remove the 8th string extension you really need to go to a thicker string. I have found a .045W is perfect. That's slightly thicker than a 6th string.
This modification makes the altoguitar so much better. It's not just a minor improvement, in my opinion. Being able to fret the 8th string is huge.