Yes, from same source as inspired the artwork in the Osprey book I mentioned:
This sign ~ is one of them word shortenings that you very often find in 15th C. texts: Õ for ON.
Likewise 'Y' written in English back then is often actually 'th' as a holdover from the Old English þ, while the alphabet also had a 'y' too (as in Ymbercourt for Umbercourt in the letters) - so when you see "Ye Olde English Tea Shoppe", it is actually 'The'. Confusingly 'ye' when written could be second person singular for 'thee' or second person plural for 'ye'... our present-day 'you' (objective) was rendered as 'thou' when used in the singular, but as 'you' in the plural.
It got somewhat more complex after 1600.