Diana 34 questions

I bought this Diana 34 two years ago at a gun show. Put it away and have recently(like today) been looking at it again. And have some questions…
First anyway to tell how old it is?
Second it has two grooves on the end of the barrel. Anyone know if it may have had a barrel brake on it? And if so is there anyway to purchase another or maybe front sights? I’m wanting to redo it to what it originally looked like especially if it’s an older model, I’d still do it if it wasn’t though. If I can obviously.

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