Either one.
I’m pretty sure this is just “fuss myself”.
A quick glance through the text turns up:
I think these fit the bill. I noticed several more from Van Helsing, and there are probably more from Harker, but the ones I quoed is representative.
ASIDE: I found Klinger’s annotations to be pretty much uninteresting. I gotta get the older ones.
I’ve read Daft Wullie and/or Rob Anybody use this phrase.
It is also used in R.L. Stevenson’s Kidnapped. Going from memory, the phrase was something like 'we were glad to get it (food) and never fashed ourselves with kitchen". Meaning we were glad to get food, and didn’t worry about fancy ways of cooking or condiments.
If I be not mistaken.
Regards,
Shodan
Very informative. Thank you! 
The first time I remember seeing it was in the ‘70s, in Asterix in Britain: "Dinna fash yersel’, laddie, we’ll dee wi’ our boots on!"
About a year later, I asked a Scottish acquaintance what it meant. He shrugged and said “‘Don’t get uptight!’”
Again, it’s just “fuss yourself”.
“Don’t fuss yourself, lad, we’ll die with our boots on.”
It’s an accent, not another language.
Well, I’d like the modern sayings or idioms.
Offhand, only a couple come to mind:
“Truth be told…”
“Far be it from me…”
Not precisely modern, but still in use.
The present subjunctive mood does get more use in modern speech than one might think, though. It’s mostly the “be” constructions that seem archaic. A lot of declarative content clauses (“that” clauses) are present subjunctive.
Ex: “I ask that you hold your questions until the end.”
The clause beginning with “that” is in the present subjunctive mood, indicating a desired state or action.
No, it’s a dialect, not an accent. But who’s picking nits? 
I went to the Wikipedia, on the belief that “accent” probably wasn’t a meaningful linguistic term, and hence was interchangeable. Instead it said:
“A dialect is distinguished by its vocabulary, grammar, and pronunciation (phonology, including prosody). Where a distinction can be made only in terms of pronunciation (including prosody, or just prosody itself), the term accent is appropriate, not dialect.”
I didn’t have to correct the grammar to be understood, nor were any of the words foreign, once the accent was accounted for. So it does seem that, at least based on the example passage, we were just discussing an accent.
So…I nit your nit nit.
Except that you substituted a different, though similar-looking, word. “Fash” is a word unto itself, so you’re looking at a change in vocabulary, not pronunciation.
Interesting. Though I do notice that the etymology of “fuss” is basically unknown (or goes back to Anglo-Irish) and that the verb definition for both words is:
Fuss: “excessive activity, worry, bother, or talk about something”
Fash: “To worry; to bother, annoy.”
So basically…they have the same meaning, come from the same region, and once accents are accounted for, sound the same. I’m not convinced that they’re different words.
In Russian, the word “баба” means “grandmother” or “old woman”. Same with Macedonian and Polish, which are related languages. It would be transliterated as “baba”.
In Japanese, there is the word 婆. In katakana, it is rendered as ばば. Rōmaji transliteration–you guessed it–“baba”. It means “old woman”.
Two words that have the same meaning, come from the same part of the world, sound alike, and look alike when transliterated. Are they the same word? No, they are false cognates.
I would guess that “fash” and “fuss” are more closely related than that, mind you, but that doesn’t mean they’re the same word. Most likely, they share a common root word, probably from French, and it’s possible that one developed from the other–if so, “fash” has the better claim to being the “original” version, as it appeared in print over 150 years before “fuss”.
I’m not sure what you mean by “once accents are accounted for”. If you mean that “fash” as spoken in one accent might sound similar to “fuss” as spoken in another, then I don’t think we can take that as useful evidence. By that reasoning, “pin”, “pen”, “pan” and “pun” would all be one word.
It’s also worth pointing out that – in terms of dialect – Scotland, Ireland, and the north of England don’t constitute a single region.