So I have been doing a thing recently for which I need to find a list of all (or at least most) of weak (regular) modern English nouns (and verbs, if possible) which were strong (irregular) in old English, like boc --> bec in old English, but book --> books in modern English, and others like it, but I have so far been unable to find any such list, so if anyone knows of one, I would be very grateful for it to be able to see it, thank you.
For the Old English nouns the division into “weak” and “strong” is less important than the division into stem types. Nouns like boc --> bec are called “root-stems” or “consonant stems” since their stems ended in consonants, these are “strong”, here's a list: https://en.wiktionary.org/wiki/Category:Old_English_consonant_stem_nouns.
As for verbs, Old English strong verbs were regular, there were 7 classes of strong verbs, each class with its own series of vowel gradation (ablaut), about 800 strong verbs, here's a list: https://en.wiktionary.org/wiki/Category:Old_English_strong_verbs.
And finaly, there were preterite-present verbs, 12 of them, lacking full paradigms and thus “defective”:
agan = to possess (owe/ought)
cunnan = to know (can)
dugan = to achieve
durran = to dare
magan = to be able to (may/might)
motan = to be allowed to (must)
munan = to remember
nugan = to suffice
sculan = must, to be obligated (shall/should)
unnan = to grant
þurfan = to need
witan = to know
Now you can go through these lists and find out which ones became regular in Modern English.