what qualifies as matching dates?

[RAW302]

How exactly do dates need to match on phone parts to qualify as a matching dates phone?  My 1950 WE302 has these dates (hopefully I read them correctly):
shell 4-3-50-2
base plate 4-50-II
ringer 4-50-II
transformer II-50-I
ear piece 4-13-50-1
mouth piece 4-50-1
5h dial 4-50

I have a 1948 302 with "circa 1948" parts.  For example the shell is 3-48 and the base is 4-48.  Is that evidence that some parts are not original to the phone?  Were they always assembled with exact matching dates or could the phone have been put together with slightly different dated parts?

Thanks,
Rachel

[Tim Mc]

Your '50 302 surely qualifies as a matching-dates phone, but technically you forgot to include the dial plate date.  For me personally to consider a phone as having matching dates, I like to also have a matching dial plate, not a later 164A like I see on a lot of phones.

While not an exact date match, your '48 is likely original since there would be some variation in the component dates when parts were pulled from inventory for final assembly, but probably by no more than a month or two.  I have a 302 with a base and 5H dated I-37 but a dial plate dated IV-36, so even though the dates don't match there is a reasonable assumption that it was original to that particular phone. 

Good question.  Is there an official collectors definition of "matching dates"?

[Sargeguy]

Good question.  Is there an official collectors definition of "matching dates"?

No

[RAW302]

Attached photos of the front and back of my dial.  I don't know what the markings mean and can't tell if any of those red scribbles on the back indicate a date.

[poplar1]

It's a Northern (Electric or Telecom) 164AX number plate. Possibly early 70s. (What year did they remove "operator" from NE phones?)

[1954NE500]

1965-66 was when "operator" was removed from Northern Electric phones for use in Ontario and Quebec on the Bell Canada network and also for use by the other Ontario and Quebec phone companies as well. This applies both the  "500" type phones and some "300" type phones that were refurbished after 1965 which was very, very, rare though.