I remember the tried to replace the Sheridan with the FMC M8 Armored Gun System, but the project was cancelled by Congress in 1996 due to budgetary constraints.
A further development of the M8 AGS was the XM1302 Mobile Protected Firepower (MPF) testbed, which both BAE and General Dynamics Land Systems “Griffin” developed, the General Dynamics model
eventually became the M10 Booker.
BAE Mobile Firepower Platform prototype.
General DYnamics Land Systems Griffin, which was adopted as the M10 Booker.