As Jeff mentioned, the water profiles listed in various places in print and the web can be incorrect and do not always provide a balance in ionic charges. The Dublin profile listed on that Beersmith site is a case in point. Either the bicarbonate needs to be increased to 300 ppm or the calcium needs to be reduced to 85 ppm in order for the ions to balance.
Regarding recommendations for using historical water profiles. Brewers should recognize that even back in history, the brewers did do things that altered their brewing water to make it more suitable for brewing. That included boiling to decarbonate, acid rests, and adding soured beer or wort (saurergut) to the mash.
I have just finished a research project that evaluated the need for high alkalinity or residual alkalinity in brewing brown and black beers. Of particular note is that the brewing water alkalinity does not need to be as high as suggested by those historical brewing profiles from dark beer producers such as Dublin, Munich, Edinburgh. That is in line with the statement above that those old brewers did alter their water.
Some of you may recall that I proposed a relationship between beer color and residual alkalinity some months ago (RA = SRM x 4.5). I proposed that equation in response to some other color vs RA relationships that had been published in some software and nomographs that vastly overpredicted the need for alkalinity in dark beers. Many seasoned BJCP judges had noted that those beers were presenting a 'soda water' taste perception and it was probably from the over application of alkalinity in those beers. Well I can now state that not only were those previous RA/SRM relationships incorrect, my formula is too aggressive too. You don't need that much alkalinity when brewing dark beers.
Unfortunately, the non-linearity between beer color and alkalinity requirements make it impossible to propose a single equation or nomograph to correlate color and RA. The excellent research by Kai Troester is the basis of that finding and interested brewers should take the time to understand the way acidity varies in classes of malts such as crystal malts, roast malts, base malts, and acid malt.
So to provide a recommendation to this brewer's original question, I offer the following recommendation for a Dublin water that would contain enough alkalinity to buffer the mash pH into an appropriate range while mimicing the original Dublin profile.
Ca 85 ppm
Mg 4 ppm
Na 12 ppm
SO4 55 ppm
Cl 19 ppm
HCO3 200 ppm
That profile can be achieved by adding 0.25g of gypsum, 0.2g of epsom salt, 0.2g baking soda, 0.2g CaCl2, and 0.4g of pickling lime per gallon of mash water. Note that chalk is not used since it cannot easily be dissolved in either water or the mash and will not contribute its intended alkalinity to the mash. At atmospheric pressure, chalk can only provide up to 55 ppm of HCO3 to water and any attempt to over dose the water with chalk will just add to the sediment at the bottom of the mash tun.