Reading out Old English like today's English?
In our timeline, we deal with Old English as a fremd tongue and learn to read it out as philologues think it would have been outspoken in yoretide. However, if you look at lands where an old form of their tongue kept being brooked in an unbroken tradition, they mostly read them out in the same way they speak out their tongue today. For a byspell, here's a quid from the book of Mencius written in Chinish writ:
>其至，爾力也；其中，非爾力也。
which (so runs the best learned guess of philologues) would have been outspoken in the writer's time as something like:
>*Gjə tjits, njəjʔ C-rjək ljajʔ; ɡjə k-ljuŋs, pjəj njəjʔ C-rjək ljajʔ.
However, in China in our time, a man from Beijing would read it out as:
>Qí zhì, ěr lì yě; qí zhòng, fēi ěr lì yě.
(One from Hong Kong would read it out as:
>Kèih ji, yíh lihk yáh; kèih jung, fēi yíh lihk yáh.
and one from Fujian would read it out as:
>Kî chì, ní le̍k iá; kî tiòng, hui ní le̍k iá.
which you may yeme ring a bit nearer but not much. Its meaning, by the way, is "that it reaches the mark is owing to your strength, but that it hits the mark is not owing to your strength".) If we did the same thing for English (which it seems likely to me that we would, if the written tradition of Old English was never broken off) we would read:
>Fæder ure, þu þe eart on heofonum, si þin nama gehalgod
as
>Father our, thou the art on heavenum, sie thine name a-hallowed.