Just IMHO but the 30 Mauser barrel is too thin to reline. During WW I, the Germans re-barreled the C96 to 9mm. Their method was similar to the pics below.
(In the third pic, you can just barely see the join line, which happens to be where the C96 barrel 'step' is located). 
Also IMHO, the 'Bolo" is not worth re-barreling. Trade/sell it for a decent C96, in 30 or 9mm.
