I have just acquired what I believe is an Air Arms Hi-Power or Sussex Armoury Jackal in .22.

The rifle is 40.75 inches long with a 15 inch fixed tap loaded barrel and a side cocking lever with anti beartrap mechanism. The top of the compression cylinder has the name 'Air Arms' embossed between the scope grooves and a serial number 17988 near the loading tap.

The black plastic military styled stock has a total length of 31.40 inches and is 4 or 5 inches shorter than the pictures I have seen of Sussex Armoury Jackal stocks.

Can the more knowledgable help me with the following...

Is this rifle an Air Arms Hi-Power ?
Did Air Arms take over Sussex Armoury ?
When was my rifle manufactured ?
Where can I get mainspring/piston 'O' ring etc ?

Any tip on re-springing / polishing / lubrication

Thanks in anticipation.
Barrie