I'll bet you grew up with this phone on the wall in your kitchen! This is the wall version of the Western Electric Model 500 desk set, designed by Henry Dreyfus of NYC J3 Hudson fame. It has the modern G type handset (with flat back so you can cradle it on your shoulder by cricking your neck) which is made of ABS and can be dropped on a concrete floor without damage. It is equipped with a 425 or equivalent speech network. The 554 set can be used as is, or you can remove the case, dial and dial brackets and mount it behind the fascia with the hook switch extending through for a flush mount installation. These phones are used but in working condition.
These were manufactured by Western Electric and its licensees, Northern Electric, Stromberg Carlson and ITT-Kellogg and came in a variety of colors, although black and beige were most common. Check with us for available stock. We can search for sets with specific options or colors.
Here's an application note on using a 554 for a behind-fascia mounting.