Need Help Determining Actual Wattage of Cheap PSU

[SuperShermanTanker]

So I have this PSU from my first ever PC build back in 2015 and that was before I learned how cheap components can cause things to not work properly especially when it's a sensitive PC component. There is nothing wrong with the unit I have but for safety reasons I pulled it out of my main workstation and only ever used it in lower powered test machines to test out a certain combo of hardware in never pulling more then 300watts through it. It's a 700watt Apevia branded PSU in it and I have only used it for about a year before I upgraded to a better 750watt Corsair branded one then a 760watt 80+ Platinum Seasonic unit. I still have this neverending question in my head though about this original unit can it actually do 700watts or if now how much can it safely do and for how long. So if any of you can help me determine that that would be very helpful in determining what it can do and if I should even keep it. I attached some images of the PSU. I can probably link some higher quality ones if asked but I compressed certain ones to keep under the file size limit.

[Mr. Scram]

It sounds like you don't have destructive testing in mind, do you?

[SuperShermanTanker]

Not when I already threw out all the cheap hardware except this PSU