As some suggested, caps have a limited life span and, yes, heat is a factor. You are sitting on a ticking time bomb. Like a new puppy, I wouldn’t go off and leave this amp with the power engaged for too long. You might find yourself with a new high wattage space heater, or a high voltage DC generator designed to push your speaker’s raw drivers forward with great velocity and hold them in place until the voice coils melt.
Otherwise, happy listening.
Yeh, I’d check into having Rowland recap them.