sorry Drexxle, but the only way that i can help you after all this on here is "IF" you bring your car around here then i will be able to sort it for you
Obviously it will cost a little as this is what i do for a living
"IF" you choose to do it yourselfr then possibly trial & error & lots of chit chat here may help you
"IF" you choose to take it back to Crash (Gary) then you takes your chances with what it`s going to end up like ,,,& what it`s going to cost you.
"IF" it was working fine in another engine , in another car,,, then there are plenty of variables thrown into the mix from then till now,,, also add to that the fact that (as David said) the jets & needles do tend to wear on the "Self-Centering" type needles over a period of time,,, there are reasons why the factory opted to swithc over to the bias or self-centering needles & it`s a bit long winded story to type here for now,,, maybe another day,,, or if you`re keen then maybe try to find where i`ve already typed it ages ago
however,,, in saying all that,,, it really does sound like a ""closer to the mark"" mixture needle would benefit.... In my opinion
there are many many needles to choose from & some are so close that people in general tend to be happy with the "close to the mark" needle,,, heaps of people tend to run their SU carbs a little "TOO" rich & although it may run fine & dandy, too rich can cause other problems without you knowing about it because of the---> """"it goes good so it must be right""" type of attitude
& there are also many other ways of """Covering up""" the sympton instead of """curing the cause""" with regards to tuning SU carbs,,, lots & lots of people do things lots & lots of different ways to effect a similar result,,, some of those ways are the right way & some are not... & often that "Similar-Result" is worlds away from being spot on,
& i`ve never seen a red needle,,, there are red springs avaliable tho, but the whole spring isn`t red in colour,,, it will have just a dash or red paint at one end
as Simon has said,,, there may have been someone use a different material to spin up his own needle (i don`t know why anyone would bother tho) & also maybe that someone used a std-ish (off the shelf) needle & then had it anodised,,, (I have no idea why anyone would bother to do that either,,, but hey---> some mothers do have em
cheers