I do feel your pain, my brother. I certainly do not claim expertise in Volvo mechanics, but can claim bitter experience, and flametraps is an area I quickly got hip to.
Volvo has a flame trap, as you are aware, and it seems to be on many models. Having owned a 240, 740 and 940, all have them. It appears it is used in recycling oil back to the crankcase, filtering it along the way. When they are clogged, the reaction seems to be to blow oil out via the valvecover. Having bought 3 models for very good prices leads me to think few know about it, and- freaking at oil consumption- unload their otherwie beloved Volvos at a bargain-basement price: MUCH to my pleasure.
To my way of thinking, oil blowing at the valve cover is a dead giveaway to a clogged flame trap. It is a modified 'T' usually of PVC, and I usually have found them on the bottom right, looking at the engine. There will be a hose coming to and from them, and pressure seems to not be too excessive (i.e. no clamps on mine). They can be bought for less than $20 USD at many parts places. On many occasions, Ive found that the basket within thetrap is removable, and is sometimes wire screen. My policy hasbeen to just replace with new, however. Hope this helps.

http://cleanflametrap.com/tony/B230F_features_v1.pdf
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html

While your flame trap is higher than earlier models' location, it's still nestled down in-between the runners for the intake manifold.
[Be glad you don't have an early model, because the flame trap would be far BELOW the manifold runners and you need tongs to reach it.

Here's a sure way to find it. First, standing on the driver's side of the car as you look into the engine compartment, find where the ribbed (accordian?) air duct goes from the AMM to the throttle body.
Next, as that ribbed duct enters the throttle body, there are two hose connections: one to a hose on the left (to the front of the car, that goes to the Idle Air Control), and the other to a hose on the right (toward the rear of the car) -- this latter hose leads directly to the flame trap.

That hose that you followed, at its far end nearer the engine's valve cover, swells in size -- this fits on top of the flame trap, which is held in a plastic holder with two other hoses: one is underneath and is a thick hose that goes straight down to the oil separator; the other, a relatively narrower hose, loops around to a connection on the back of (i.e., on the engine side of) the intake manifold. You probably need to look straight down from above, as if you were very tall, or standing on a stool.

You have to pry the hose up off the plastic holder -- but don't try it until you have a replacement holder (as well as the flame trap), because very often (depending on how old the components are, or if the previous owner bought a non-Volvo brand plastic holder) either the plastic holder breaks off the nipple to the narrower hose, or the hose splits because it's so old and stiff (it's no longer compliant).

If you AND the previous owner used good quality synthetic oil, you probably don't have to even clean, let alone replace, the flame trap -- many of us synth oil users have found the that trap never gets dirty anymore.

You can replace the long hose to the oil separator with an even longer hose, which places your flame trap high up over the intake runners and really easy to inspect. I've done that (just in case my use of synthetic oil isn't always foolproof in the future). Installing the longer hose is a bit of a pain, however, but it's worth it in the long run -- like if you keep your car for the next ten years or more :-) .]

Anyway, in summary, if you followed the hose from the mouth of the throttle body, you shouldn't have any trouble ending at the flame trap.
Hope this helped.