Another opinion (everyone has one): You will often spend an inordinate amount of time (time is money) chasing problems on an original Phase Linear control board. Then get frustrated with lifted solder traces, burned board, broken wires, ordering new parts, etc. Ask me how I know...
Sometimes it is just faster, easier, and better to replace the original defective obsolete control board when there is a much better WOA product available for not much money. The amplifier works better, still looks original, and will be reliable for a long time. No real downside?