Yet another Marantz 2270 output transistor question

I have read every thread on the forum and yet have an unanswered question.
I traded recently for a 2270. One of the newer ones with all the mods and S40442 / 443 output transistors. But, one output on one side is shorted, C to E. After removing all four outputs I checked the rest of the amps out and they are fine. The drivers play well into 1k ohm loads so there don't seem to be any thermal intermittants either. My instincts tell me to replace all four outputs with OnSemi outputs and be happy. But the pureist in me sez to just replace the shorted ones and leave it original.
Mouser currently has the MJ21193G / 4G replacements in stock and the price isn't bad. Could someone tell me if there is a compelling reason to upgrade all the outputs, or not? I'm kinda stuck on this point for some reason. I also intend to re-cap everything to as this is probably a keeper.

I would just install the On Semis and never look back. Don't forget new mica insulators with a thin film of thermal compound on both sides.
There is a thread on AK about adding fly back diodes across the outputs, you will want to do that.
There are also a few service bulletins that may apply, check out the service manual on hifiengine, they are in there.
Here's a parts list that you may find handy. Be sure to check it against what's actually in your 2270.

Tom

Thanks very much for the tips. I was a bench tech back in the 70's and am fairly familiar with this stuff but it always helps to get others opinions. One thing I've learned since restoring these old Marantz's for my collection is that restoration is very different from repair. I find problems that simply were not present when the equipment was newer.
What's with the "flyback diodes"? I've seen such a thing on power supply pass transistors but I have to say I don't recall ever seeing that done on an audio power amp.