On Mon, 11 Apr 2016 09:06:48 -0700, Jeff Liebermann
wrote:

On Mon, 11 Apr 2016 07:23:49 -0400, "J. B. Wood"
wrote:

On 04/10/2016 04:42 PM, Jeff Liebermann wrote:

Are you sure about the model number? The SC number was SC-554 while
the WE number was 2554.

SC-554:
https://www.youtube.com/watch?v=cDP6I8bEP8o

WE 2554:
https://www.youtube.com/watch?v=VedsBJfsLlo

Thanks for the response, Jeff. The number stamped on the back of the
instrument is S-C 2554BPM. Perhaps the "2" designated a DTMF type dial?
Sincerely,

Ah, that's a better number. There's one for sale on eBay if you need
parts:
www.ebay.com/itm/STROMBERG-CARLSON-2554-BPM-Wall-Mounted-Single-Line-Corded-Phone-/281979044418

It's impossible to get into a discussion on adhesives without everyone
recommending their favorite potions, concoctions, and methods. I'll
just make things worse.

My guess(tm) is that the plastic in the phone is probably ABS (acrylic
butyl styrene) which will weld nicely with acetone solvent. There are
overpriced potions available that are mostly acetone, but might
include other solvents (MEK, toluene, etc).
http://nerfhaven.com/forums/topic/18527-intro-to-solvent-welding-plastic/

Superglue (cyanoacrylate) is too brittle and mutilates acrylics.
http://info.craftechind.com/blog/bid/323475/Stick-to-it-A-Guide-to-the-Best-Glue-for-Plastic

Urethane adhesives, such as Gorilla Glue, don't do well with many
plastics because they do NOT contain any solvents. Fortunately, the
phone switch insulator (or whatever it's called) sees force in only
one direction, so marginal adhesives will probably work, for a while.

Just to muddy the waters, I've been learning plastic welding using
some home made brass nozzles attached to my SMT desoldering station
hot air gun. When it works, it works great. When I do something
wrong, it destroys the part. Plastic welding works best for me on
large plastic parts, and not so good on small plastic parts.

I'm also a fan of hot melt glue, but that's not appropriate for this
job. However, if you do decide to try hot melt glue, be sure to get
the correct type of adhesive stick:
https://en.wikipedia.org/wiki/Hot-melt_adhesive

Good luck.
ABS=Acrylonitrile butadiene styrene.