In the recent piece of briar wood I found a big hole.
Briar block was big enough to change the placement of the chamber, to save to wood.
Even moving the chamber about 1 cm was not enough. The hole was still on the pipe. Fortunately not to the chamber. But rustication will help to hide the hole.
Total lenght: 152 mm; Bowl diameter 32mm; chamber 18 x 42 mm
Used material: briar block with the hole :), ebonite, teflone cone, aluminium for the rings.