Bill,
Had the same problem with the sink trap on my '90 westy.
I got lucky and found one in a RV supply store.
It looks almost identical to the old one.
On the label it says the following:
P trap assembly
attaches to basket strainer. Including trap body,
3/4" hose connector, cap.
mfg by MFG Par, Nameco Tme of Canada, Ltd.
Part # 12-001
U.S. Price: $12.58
Maybe you will find one in a rv store nearby.
Note about installing:
The round bowl of the new trap is held on by 4 screws on
the outside.
The old trap was held in place by a small screw in the center,
which is prone to leakage and failure.
To install the new sink trap, you have to remove the old part
of the sink trap body under the sink from the basket strainer.
Once installed, it's a big improvement over the original.
Hope this helps.
Harald
'90 westy

Bill wrote:
> Any ideas on where to get a sink trap for an '84 westy?  Bently shows two
> types, one looks like something that I could get at any hardware store,
> but mine is the other type, like a 2 inch length of pipe with a half
> sphere on the bottom, with the drain hose comming off the side (or at
> least it used to, before it broke!)  I am in the process of removing
> most of the camper interior, fixing some seam rust, and re-installing
> everything, and  somehow broke the trap in the process.