Hi slow_runner, I forgot it was you, the owner of a beautiful Victory in New Zealand.
I hope that everything is well with you.
Back on topic: perhaps you could try Weihrauch front sight inserts for your Victory?
Otherwise it is probably doable to make them using a plastic disc?

With the Ace, you will see how easy pumping can be.
But I agree, the Victory is a very good gun too.

Locking plate and missing sights:
front and rear sights? I believe that Protek Supplies in the UK has an original Ace rear sight for sale.
Front sight will be a bit harder to find.

Locking plate: I might have a spare one for you, if you want. Just send me a message if you decide to buy the Ace, and need parts.

Cheers, Louis