Safe to Use Old Homebuilt XL/XE Power Supply?

[electronizer]

While going through a box of Atari stuff I got back in the day, I found this homebuilt power supply:

 

 

 

 

I made a quick schematic drawing; the only component I couldn't get a good view of was the small electrolytic capacitor across the output. I'm guessing it's around 10 or 20uF.

 

 

Does anyone recognize this design (e.g. did it appear in a magazine or other publication)? Any thoughts on its quality? Based on the schematics I've seen of the "official" power supplies, this one seems simple in comparison—only 7 components!

 

I'm a little short on good XL/XE power supplies. Assuming that the components are still good and I get 5V at the output, would this be a reliable supply to use?

[pirx]

Apple/Samsung style USB chargers are generally perfect, would dig in a drawer, find an orphaned charger and make USB to DIN7 cable. this contraption is impressive and should be OK, but...