[bobs bots]

Dan has raised a good point,
If you can find some perforated sheet you can make a box out of this and rely on passive ventilation. I've found a photo of the KL7212 now, It is built on a shallow U base made from aluminium? So one could use a sheet of perforated material for just the top and sides , and screw it to the flanges of the 7212.
(It should be noted at this point, that here in Australia, we can't just stroll down to the nearest ACE hardware and pick up a 2ft square sheet of perf. metal)

For best results the supply should be mounted vertically, with the transformer at the top, and the capacitors at the bottom. The transformer will be dissipating around 70W at full load and 35W at idle, so will create a chimney effect and draw cool air over the capacitors. The bridge rectifier will be dissipating around 24W at full load, and the capacitors dissipating around 6W total.

I've also discovered an error in my earlier post, turns out your average electrolytic capacitors are rated for 2000 hr life at full ripple current at rated temperature (I was mislead by some other high performance capacitors I was dealing with earlier). The KL7212 uses 2x 10,000uf @ 80V capacitors , I don't have the part number , but typically this value capacitor has ripple currents around 6A at 85c for 200Hrs, and starts with 30milliohm ESR (each). So If you want to drive this power supply at full rated output for 24Hrs/ day at 40C ambient, you will definitely need some supplementary cooling to keep the caps well below 85C.
On the other hand if you intend using it for hobby CNC, say 20Hrs/week, in say 20C ambient, and your loads are less than full rated current, (and I would expect this to be the case), then you will get a long useful life out of the unit, even with quite modest natural ventilation.
BobT