if you did secure permissions then thats good - the question would have been asked anyway, and eventually asked again... it's part of the process and happens to every project dev lol
when posting a screenshot to show your progress, perhaps you might want to consider clarifying to people that those things are just placeholders (not part of the final), and perhaps give a nod to who the original author is of the thing you are using? it's just a respect thing IMO, thats all :)
btw - just a heads up as far as LCARS go, if any of them are Joe Ralat's LCARS, he is very strict about them being used in any screenshot or game without credit being posted directly on the image itself (in case you didnt know that)...