The Music Link MA-24 is the original but export version of the slightly later japanese MA-7A.
Before that, the 24 was the Marantz MA-6 and, briefly the MA-7. And before that, it was the ESOTEC Ma-5. And before that the Model 18.
Visually, the MA-24 retains the basic top grille of the old Ma-5 but inaugurates the roundy on/off button (after the square and top-lit pad of the MA-6 and MA-7) ; the MA-7A has a thick aluminium cover ventilated by four rectangular spaces.
Inside is much better than the old Ma-5 with an OFC toroidal trafo, copper everywhere and a better shielding of the toroid trafo and i/o boards to avoid hum and noise.
30W in pure Class A, MOS-Fet outputs, 70µ copper epoxy PCBs, 2x 22,000µF/50V ELNA For Audio caps, gold-plated and amagnetic input plugs, 24k gold-plated output terminals and enough current to power difficult speakers.
Unlike the MA-6 and MA-7, MA-24s have no four-way switch for INV / NORM / BTL+ / BTL- selection so as to allow phase+ / phase- amplification of the signals coming from the SC-22 line preamp - just hook properly !
Other than minor specifications differences, the MA-24 and MA-7A are entirely equivalent,
Real European MA-24s (modded for bi-wiring) here ; note the "GL" denomination on the box, which means they were probably planned in black as well...
Highly modded ones here (btw. unlike what is stated there, ESOTEC and Music Link are two completely different series and not a mere US/EU marketing separation) and here
A real pair of MA-7As here ; note there is no Music Link tag anywhere, front, back or manual.