Sorry for the late reply as I didn't see this until now.
There is no reason for there to be a difference in English loanword usage in North Korea between the border area and the far far North. Remember, the DMZ is a tightly sealed border and there has been virtually zero cross-border exchange that would influence the language since the Korean War. If we were talking about normal national boundaries with some cross-border linguistic exchange then there would be a gradient of linguistic features taken from the neighbouring state near the border and diminishing as you move away from it, but with the DMZ there is no such thing.
찍개 is a recent South Korean neologism for 'stapler'. There is no reason that North Korea would use the same word. I don't know what they call staplers in North Korea, though.
Once again, the point is that English loanwords were being used in Korean before the division of the peninsula, and afterwards, North and South Korea followed completely separate paths of linguistic evolution. There was no way for people near the border regions to be influenced by what people were speaking on the other side. You might flip the question and ask whether South Koreans near the DMZ are more likely to use pure Korean words due to North Korean influence, and again the answer is no for the same reasons.
도꾜 is the traditionally common spelling for Tokyo that is based on maximum phonetic similarity. In South Korea, the spelling was reformed to 도쿄 to conform to standardized rules about how to write Japanese loanwords, where all non-initial "k" sounds were to be mapped to ㅋ. So this is more of a phonemic spelling. Roughly speaking, "phonetic" refers purely to the sounds, while "phonemic" goes into the more abstract level of grouping the sounds that are considered mere variations of a single sound to the speakers of that language. However, due to widespread resistance, the South Korean reform didn't go all the way in making it phonemically regular—otherwise, we would be writing 토쿄 instead, using ㅌ everywhere for "t" (in concession to the traditional practice, we write ㄷ for initial "t").
This reform took place in the 1980s in South Korea, and didn't affect North Korea, which still writes 도꾜 for Tokyo. It has nothing to do with Russian pronunciation. If we imitated Russian pronunciation, it would come up as something like 또끼오 or even 또끼워.
Place names side, I like that Korean orthography is morpho-phonemic rather than striving for purely phonemic spelling. The same morpheme tends to be spelled the same everywhere it's used, which promotes reuse and actually tends to make writing in bulk easier. It also isolates the written word from shifts in pronunciation over time a little more, something that hangul otherwise runs into problems with anyway.
In practice the orthography is sort of a middle step between the hanja spelling for many morphemes and their pronunciation. Multiple hanja end up mapping to the same hangul block because they're homophones, so there's some information loss, but spelling is morphemic enough that you can recognize the same morpheme in different arrangements. If you can guess what hanja it might be though you can often understand a word more deeply.
There is no reason for there to be a difference in English loanword usage in North Korea between the border area and the far far North. Remember, the DMZ is a tightly sealed border and there has been virtually zero cross-border exchange that would influence the language since the Korean War. If we were talking about normal national boundaries with some cross-border linguistic exchange then there would be a gradient of linguistic features taken from the neighbouring state near the border and diminishing as you move away from it, but with the DMZ there is no such thing.
찍개 is a recent South Korean neologism for 'stapler'. There is no reason that North Korea would use the same word. I don't know what they call staplers in North Korea, though.
Once again, the point is that English loanwords were being used in Korean before the division of the peninsula, and afterwards, North and South Korea followed completely separate paths of linguistic evolution. There was no way for people near the border regions to be influenced by what people were speaking on the other side. You might flip the question and ask whether South Koreans near the DMZ are more likely to use pure Korean words due to North Korean influence, and again the answer is no for the same reasons.
도꾜 is the traditionally common spelling for Tokyo that is based on maximum phonetic similarity. In South Korea, the spelling was reformed to 도쿄 to conform to standardized rules about how to write Japanese loanwords, where all non-initial "k" sounds were to be mapped to ㅋ. So this is more of a phonemic spelling. Roughly speaking, "phonetic" refers purely to the sounds, while "phonemic" goes into the more abstract level of grouping the sounds that are considered mere variations of a single sound to the speakers of that language. However, due to widespread resistance, the South Korean reform didn't go all the way in making it phonemically regular—otherwise, we would be writing 토쿄 instead, using ㅌ everywhere for "t" (in concession to the traditional practice, we write ㄷ for initial "t").
This reform took place in the 1980s in South Korea, and didn't affect North Korea, which still writes 도꾜 for Tokyo. It has nothing to do with Russian pronunciation. If we imitated Russian pronunciation, it would come up as something like 또끼오 or even 또끼워.