brass hammer rails repair or replace?

[Newton Hunt]

It seems to me that the pivot point of the hammer center pin will be in
the same plane regardless of the attachment system.  I would seriously
consider modifying the rail to accommodate a modern flange.  If you have
access and use of a router you can route a flange retainer (read a
flange bead) to glue upon the old rail or route the same into the old
rail.

Then you have the task of marking for flange screw holes.  A good
transfer can be made from the let-off rail  You can get new buttons with
fresh new felt from the supply houses.

Installing the new butts (and I agree with the previous post about
quality parts), spacing , traveling, etc., is the same for any action.

I would also change the damper felts, and while you have them in hand
check all glue joints and pinning.

Have fun.

        Newton