Looking for a recommendation on a 24VDC power supply w/ charger for two 75 amp hour 12 v batteries, with a battery "revert" circuit, which is typically a pair of blocking diodes.

When we used to do this on offshore panels we used to have the batteries floated across the PSU. This was deemed to be more reliable than using diodes in circuit, and give a much smoother 24v DC, also you could use a simpler PSU. Possible down side was that actual '24v' was about 28.8v when on 'float charge', but if the supply failed the voltage would just decay as normal for battery system. In any case with a pair of blocking diodes the output from the '24v' needs to be higher than the battery voltage which for 2 x Lead Acid 12v batteries is usually around 14.4v = 28.8 when on charge, otherwise the batteries will end up supplying the power. So you will need nearly 30v to ensure that the PSU is actually supplying the power.

I saw this done with both Lead acid and also wet nickle cadmium cells.

In the UK Dale electric used to supply the kit, but this was 25 years ago, dont know if they still do, but I notice you are US based.

Sola makes a 24VDC UPS that might fit the bill. Not sure what cost is off-hand.