John, I have always liked those "apartment" phones. That's the only pre-handset type of phone I'd ever have.
The dates on older WECo equipment used Roman numerals. Example: IV 31 would indicate 4th quarter of 1931. Once WECo started using Arabic numerals for day, month and year, Roman numerals would sometimes be used to additionally indicate the shift during which the component was manufactured, such as 10-15-61 III.
Jim, exchange names were used by AT&T nationwide, so for sure CYpress existed (and still does behind the modern numeric designations) in many communities across the country. As witnessed by the grand total of two phone numbers that my family had (including the one serving my current home), a number beginning with 29 could exist in more than one switching office. Our first number that began with AXminster-6 (aka 296) was served from one office, while our second number CYpress-5 (295) was served from another.
Believe it or not, the AXminster office still exists in-house at AT&T as "SJAX." The CYpress number originates out of "SJMN," the "MN" denoting the "Main" office in the big windowless building downtown. SJAX also contains the old CHerry exchange, along with many newer prefixes assigned long after alpha-numeric was phased out. Some of the other local office names still in use are ALpine, ANdrews, BAldwin, and CLayburn. This is the case all across the original Pacific Telephone territory, as I learned from working in the Pacific Bell business office for several years. After having spent 17 years working in craft as well as management positions for PB/SBC/AT&T, I can tell you that among the telcos old habits die hard, or as with exchange names, continue to live on long after having been phased out for practical purposes in the mid 20th century.
Independent telcos had their own exchange names that were separate from AT&T's. I found an old manual (no dial) WECo model D1 phone in Tucson several years ago that has a GIbraltar number card. I'd never heard of that exchange, and noticed that its handset was an F1W type rather than a plain F1, which is otherwise identical in every way. The W indicates the phone was manufactured for an independent telco that had no hardware manufacturing facility of its own, so I presume that's where GIbraltar comes into play.
I've provided a link for more about exchange names, and have attached a couple of pictures for you and John. I researched the GIbraltar exchange not long after I got that phone and found that it exists/existed in a rural area of Arizona, so that seemed to confirm my suspicions. John, if you look closely at the inside cover of the subset (ringer box like your 553 uses) you'll see the Roman numeral I indicating the month and 32 indicating the year.
In addition to the link below, here's one for the same site that provides names according to the first two digits (interesting that CLayburn is missing from the "25" list, and YOrkshire is not on the "96" list so I suspect there are quite a *cough* number of discrepancies):
[this post was last edited: 9/13/2020-19:27]
