[AHI]

Is the barrel 28 inches as marked?

 

[AHI]

That's why I asked if the barrel was 28 inches long as marked.

 

[AHI]

Do Beretta barrels indicate which series of Optima chokes?

Barrels are marked Optima for optima choke, Optima HP for Optima HP, Never seen a optima + . So that one I don't know But it should be.

I do know one thing, some of them, with a little effort, will interchange with disastrous consequences.

I know the treads are the same. This is a bad thing IMO. Gave up telling a guy at my club. He is running optima chokes in an Optima HP barrel. So far no apparent damage.
Optima definition: a condition, degree, amount or compromise that produces the best possible result

 

[AHI]

I recently purchased a second-hand AL391 Urika, supposedly built in 2005. Unfortunately, it did not come with any chokes so I need to buy them.

Could you not just ask the person that you purchased the gun from? They kept the chokes for a reason. They must expect to use them. Or is something else going on?