Dave,
I have something in there similar to the slower -turning blade one you mention. Now working about 10 years. The original factory was noisy til it finally failed. 
It's like the one in my desk-top that is very quiet. I learned about fans while building computers.

With dual batteries for 15 years I've never run down to the point of needing a jump.Another mod I learned from Karl Mullendore when he was visiting years ago was increasing the size of the flame spreader by 2 notches. Whether that actual is an improvement I can't say.

I also put the fridge upside down 24 hours after I remove one, to burp it.

If the stock fan works I leave it and just lube the bearings.
Some of this info i got a long time ago from an article titled "Fridge Madness"
The thermal paste has silver in it and comes in a tiny tube. 
Usually I find this switch screws are loose.
I test run my serviced fridge from the vehicle" propane supply for a day before reinstalling.

I've kept mine running for 17 years by periodical burn chamber maintenance, and cleaning the nozzle in denatured alcohol.

Robert
1982 Westfalia

> > Here's a tip for those servicing the fridge: Replace
> the factory fan with a computer fan. They are brushless
> type, use less amperage and are quieter. Lube the computer
> fan bearing with light machine oil before installing. Peel
> back the label and put one drop, then seal it over�
> with the label. Use a small amount of thermal transfer
> compound like the type used for computers between the
> thermal switch and the fins. Robert 1982 Westfalia
> 
> Hi Robert,
> 
> I agree with the oiling technique, great way to get more
> life out of a fan that's gotten sloppy.� I think using
> compound under the thermostat button is overkill, but
> there's certainly no harm in it.� But emphasis on very
> small amount, as the paste itself is a lousy conductor and
> should be in an almost invisible film to fill in
> molecule-size gaps in the contact face.� Any more and
> it starts working against you.
> 
> On the fans, though, I have to disagree.� Typical box
> fans draw more current**, move less air and make a nasty
> whining noise because of their small high-speed
> blades.� They're also inefficient in air moving because
> of the small blades, which is why they have to spin so
> fast.� They *can* be very quiet but only at the expense
> of moving very little air
> 
> The OE fan draws 50 mA, has a big slow-turning blade that
> moves a lot of air quietly, and if you can more than just
> barely detect it it's because the commutator has worn out
> and gotten noisy.� The Fridgemate/Valterra fan designed
> for the purpose is IMO a superior replacement with an even
> larger blade (be sure the insulation clears it) and similar
> 50 mA draw.� Here's a drawing how to modify the stock
> bracket to fit it: http://pws.prserv.net/synergy/Vanagon/Fan_bracket.gif
> 
> **I've never seen a box fan more than an inch in diameter
> that drew less than 50 mA, and only one that drew that
> little.� Even the ones the size of a quarter typically
> draw 80 mA and move almost zero air.� I've got box fans
> here ranging from 20 mm up through eight inches, including
> ones that draw a quarter amp or more at 110 VAC.� I've
> got a 3 1/2" 12V fan that draws almost three amps and you
> can feel the thrust when you hold it, and a 40 mm one almost
> 30 mm thick that spins at close to 20,000 rpm and has fixed
> blades for the airflow to bounce off.� I've been in
> love with box fans since Rotron invented them and called
> them Muffin Fans.� But I've never seen one that I
> thought was a really good replacement for the fridge
> fan.� So sitting on my pile of oh say a hundred various
> box fans I still paid $25 for a FridgeMate fan to fix my
> Westy.� Box fans are by nature noisy pressure drivers,
> and what the fridge wants is a quiet volume driver.
> 
> Yours,
> David 
>