You wrote:
Brake failure light did not come on when hand brake was engaged. That still is a problem but I think it might be a bulb???????

1/2 right. When hand brake is engaged, "Emergency Brake" light should come on. Not the "Brake Failure" light. Probably a bad bulb in instrument cluster, but you can also check the switch located under tip of brake handle.

You wrote:
The Bulb Failure stayed on when the low or high beams were turned on. That still is a problem... followed by details re. Bulb Failure going on/off with brakes sometimes.

In my experience, the Bulb Failure detector is pretty good. It's irritating, but is reporting an actual situation. Try to find what it's telling you about.

You can replace it, but considering it's detection method, and the cost of the part, you might rather do all the below first - - -

The Bulb Failure detector detects a difference in current draw between the left and right side of car. If all is well the current used is the same on both sides, of course. Sensor has separate circuitry for each system it monitors: headlights, taillights, etc. Somehow they made it work with a 3rd [center] brake light in the system.

Be aware that different brands and different ages of bulb can have a different electrical load, and so will trip the detector. A matching pair of new bulbs sometimes cleans it up.

You report the problem when turning on the headlights or brights.
Could be you have 2 different brands of headlights AND 2 brands of brights.
Also, headlights & brights have in common - -
Front small lamps ("parking lights") and
Tail lights

So, check and clean the small front lamps and the whole tail light assembly.

The tail lights share a ground with the brake lights, this could be the cause of the Bulb-Out light going out sometimes when you hit the brakes.

Often the problem is a bad (dirty) contact on a bulb, bulb holder, or the assembly the (tail light) bulb holder goes into. Clean them all up with electrical cleaner and emery cloth, or scrape clean with a pocket knife or such. Sometimes I've had to bend out the spring contact so it makes better contact with bulb. Also check and clean the connections to the "circuit board" the bulb holders fit into.

If you really want to get into the tail light assembly on a 240 wagon, it comes out. Find 2 nuts accessible in rear of lamp assembly. Hit with PB Blaster to loosen if rusty, and undo the nut. Housing pulls off rear of car. If it's really awful, with melted plastic and burned up contacts, get one from a junker, or from fcpgroton.com (theirs is about $80 or so).

Once I got mine all cleaned up, I haven't had the Bulb Failure light go on since, in about 20K miles, for me about 6 months.

Good luck!
It's work you can do, and the shop guys often don't like doing it because they would rather get flat book rate for jobs they can do faster than book time.