OK, that's good because pins 8 and 11 are C1 and C2 on the TK494 and pin 1 is one of the inputs to one of the error amplifiers.
See where pins 9 and 10 go. They may even be tied together.
The next thing to look at is what is connected to pins 5 and 6 which are the timing network for this device.
for 50/60 Hz, the capacitor connected to pin 5 will be around 1uF, and the resistor connected to pin 6 will be 20k (60Hz) or 27k (50Hz) (both approximately)
If these all seem right, I'd be looking at a TL494 as a replacement.
I would be looking at what is connected to pin 12 to make sure it hasn't been damaged by over voltage.
The next thing to look at is how those mosfets are connected. you need to test the remaining good ones to determine if they are P or N channel, and if they're all the same (both in a pair will be). I suspect they're all N channel.They'll be 500V devices in all likelihood, and capable of around 10A or more.