I've never seen Cyrillic written like that before.

Chucu said:

I've never seen Cyrillic written like that before.

This is stylized to Old Russian, its hardly readable at first glance and probably Lubok parody.

It would be perfect is someone could stylize it to Old English ("thou").

And now we got another ancient as mamonth's crap writing ended up here and translated.

Chucu said:

I've never seen Cyrillic written like that before.

It's called "Старо-славянский" ("Old-Slavonic"), got spread from approx. IX-XI centuries... IMO it looks more like Cyrillic, stylized as Old-Slavonic.
Remnants of Old-Slavonic still used in those huge Holy Bibles at ortodox churches.

Reading an entire page of that, weathered, with shaky hand-writing, must be a herculean task.

Saladofstones said:

Reading an entire page of that, weathered, with shaky hand-writing, must be a herculean task.

It's like reading in another, non-native language with different symbol system.
For example, as hard as reading any hand-writing from Eastern Asia or Arabic for those who learned only Cyrillic or Latin alphabets.

I’ll translate, because the picture is really funny.

But I’ll warn, that the line on the image is a mashup of styles ranging both geographically and time-wise, which can never be translated properly. It’s also (intentionally?) ends stupidly broken and has several mistakes. But a speculative translation can give you this:

Сѥ (This) же (before you) ѥстъ (is) Мами (Mami) Томое (Tomoe) иже (which [to the]) москъвьскаѥго [Muscovy] стрельчьска [Strelets] воиньства [army] ѥстъ [belongs].

If anything, that script style imitates viaz’ (here in red: https://upload.wikimedia.org/wikipedia/commons/thumb/6/64/Apostol_1564_Frontispis.jpg/1280px-Apostol_1564_Frontispis.jpg), which is purely ornamental, usually you’d see book or chapter title done with it or on physical objects where there’s a lack of space (church bells come to mind). The point of viaz’ is to fit words on a single line, be it a heading or a ring inscription on a bell.