Don't know if I already asked it, but is Latin set for Uletha or is it just a provisional solution?
It takes half an hour to devise a sound shift using this tool.
Here you can reference various real-life sound shifts, because one of the easiest ways to make a conlang is for example by applying Germanic, Slavic or Celtic sound shifts to Vulgar Latin or vice versa adding Romance sound shifts to a non-Romance language.
This is a good starting point for Vulgar Latin vocabulary. I think that just deriving 100-200 words is enough for place names.
Stjur's mother tongue Romanian is a prime example of Latin influenced by other languages (Slavic, Greek and to a lesser extent Germanic and Turkic if I am correct). I think that OGF is fairly international and everybody can use their languages to influence a new conlang.
So rather than just using Latin, which I don't see as being used except for in religious or very official matters in a country between Pretany and Medwedia, we should just create one, or better, multiple Romance conlangs. I think that it would be much more fun.