My boldings, above -- I would be delighted for there to be available, comprehensive and learned books on the history of railways in the different countries of Europe (and elsewhere on the globe !); I would reckon that to a considerable extent, there likely are -- but (
@181 , you are perhaps overall more optimistic in this, than me): that wretched Tower-of-Babel business does much frustrating here. A matter touched on in the recent thread in the International Transport sub-forum, "Can anyone recommend a good book on the history of French railways?" (first post 28 / 3 / 2020). Mention made there, of claimed-as-excellent histories of the railways of France (in three volumes); and the Netherlands; by Francois Caron and Gus Veenendaal, respectively -- strongly implied, though, that these works available only in the authors' native tongues; so unless one has a reasonable mastery of the languages concerned, one is out of luck. There are exceptions: Chester's book on the n/g of Bosnia-Herzegovina, as you cite; and I think there has been some attempt at an English-language history of Russian railways (by J.N. Westwood? -- this off top of head).
I'd imagine (speculation, not hard knowledge) that there are indeed worthwhile books on the history of railways in, at all events, many of Europe's countries -- but, in those countries' respective languages. In many lands of Europe: railway enthusiasts as such, are few in number (in others, they are plentiful; I'd be prepared to "bet the farm" on there being plenty of published material on the history of the railways of Germany [a scholarly land, anyway] -- but in German) -- however, virtually any country in Europe will have railway professionals; and scholars of history in "general" scope; who would be likely to have an interest in what came about, and how, with their country's railways from inception to the present day -- hence likelihood, I feel, of the existence of books fulfilling that interest, re assorted nations.
Concerning the ideal as above, of books on the railway history of each country in Europe: given on the part of a fair few people, heroic diligence for no financial reward -- that could be feasible. Translation would be necessary, by persons with a decent command of the relevant foreign language, and of English; commercial success of such translated works would be unlikely, by reason of -- as you surmise -- a fairly small number (at best) of people, being interested. A role for what I believe the trade calls "vanity publishing" -- wanted, folk ready to donate, variously, lots of time, and no small amount of money, to an excellent cause. While in principle, I applaud the idea; it must be said -- don't look to me for actual contribution: have enough competence in French and German, to be able to give it a shot -- but I'm elderly, terminally lazy, and penurious. As so often: "you [general] go ahead and be a hero -- I'll cheer you on from the sidelines
".