What is the reason for this behavior of fonts?

Question

Character encoding

Colleagues who are well aware of the structure of fonts, can you tell me?
There are two fonts: Phonetic Newton (Type 1) and Newton Phonetic (OTF)
In the first, the transcription symbols are scattered strangely: at the beginning of the code table and towards the end (61 thousand - 62 thousand) duplicates. And still in the middle of the range.
In the second - compactly at the beginning of the table.
Weird #1.
Let's say I'm using the Type 1 version of MS Word. I insert a symbol through the "Insert symbol" dialog, select it in the table. The symbol appears, but its code is not the one that was visible in the dialog, but the code of the duplicate glyph from the end of the font table! We wrote a macro to replace the character code (the macro processes the entire word file). The replacement occurs, but if you look at the code, it will again be from the end of the table!
Weird #2.
I look at both fonts in Font Expert. The second font in "Windows Encoding" and "All Defined Characters" modes looks the same. Well, with the exception of dummies, which are not defined, but in the "Windows Encoding" table, there must be.
But in the first font in the "Windows encoding" mode, glyphs appear on the codes, which disappear in the "All defined characters" mode.
What the hell? It seems that some codes of the first font are some kind of aliases for other codes in the table. This would explain both the first strangeness and the second ...
Misunderstanding of this situation already annoys me rather. I began to study Fonts & Encodings (Yannis Haralambous), but so far I have not found an answer.
I ask those who know to explain!

Answer 1

I will assume that the first area contains characters from the ASCII set, and at the end they are duplicated.
Replacing encodings - could you give two codes, one that you choose, the second - with which it will be replaced by word? Again, I will assume that these are two different encodings, the old and the new.
The whole problem is that earlier in the ASCII encoding, the first 128 characters were common, the rest were different. And then on the second 128, then their codes appeared in Unicode, and Unicode counts just the same from 256 characters (0-255 are busy). Accordingly, in some fonts there are characters both in the range from 128 to 255, and further, already in Unicode encoding. And now the Unicode encoding is a priority, because the system replaces your selected characters with them. I read about this, it seems, from Kirsanov. This is an assumption, without font files it's hard to say, and I'm not that expert.