Broadwood hammer travel regulation and butt spring replacement

[charliegrey at mac.com]

I am trying to do some regulating and refurbishing on a Broadwood  
upright (46") 1906 vintage. The action is different to anything I  
have worked on and I believe it is the Swander type. In any case,  
there are little springs everywhere. Many of the butt springs are  
broken of with the end embedded in the butt. I purchased some butt  
springs from Schaff but am stymied as to how to install them. Is it  
possible to remove the broken end of the old spring and if so how? Or  
do I try to drill a hole for the new butt spring as close to the old  
one as possible?
The next problem is trying to regulate hammer travel ie., papering  
one side of the flange. On this piano there is another spring at the  
base of the jack that catches a thread from the hammer through a slot  
in the jack. It is very easy to release the thread to remove the  
hammer butt but devilishly difficult to reattach it once the hammer  
butt is back on the rail. Anybody had experience with this little  
doozy? I have removed a number of hammer butts and the best I have  
been able to achieve was 25 minutes to re-install with alot of  
talking to the piano and myself. At this rate I could spend the  
better part of the spring playing with springs and threads.
thanks for any advice,
Charlie Grey