aint nothing wrong with them
someone one here did a build along about a year ago,look in the past post on the "how to/build alongs" section
as far as soung goes,you should check that as you are putting the peces together(that way you can adjust each piece for best sound)
then just mark the pieces where the fit together and make the best sound,then glue them up.
once you have them glued together,you can still adjust for better sound.
you just need to work on lip placement on the tube.a little rubber o ring,that fits snuggly,on the end piece(where yor lips go)
makes a nice stopper and placement for your lips.once you know where your lips work best just put the oring on upto that point
next time you will know right where your lips go on the call