For a grand, upright, or spinet that no longer holds its tuning at pitch, pinblock consolidation can offer a pragmatic and relatively inexpensive solution. CA glue is soaked into the pinblock at the feet of the tuning pins and left to cure overnight. An upright or spinet must be tilted onto its back so that the low-viscosity glue goes into the block and doesn't make a mess.
This repair has the benefit of being passive - nothing has to come apart or be replaced. The glue wicks into the pinblock, reinforcing the area around the pins and increasing surface contact between tuning pins and pinblock, thereby creating enough friction to hold the tuning at pitch.
This glue will not repair delaminations or fill cracks, however. Since such structural failures may not have a visible symptom, there is the risk that the repair will not succeed (about 1 in 50, in my experience). If the piano is to receive other work, this repair comes first, with its success a contingency for proceeding.