This was easier than I thought. This "SISCO 90 Model Target Master" air rifle, despite having rusty metal surfaces was practically unused and the factory grease had turned into tar. I opened up and cleaned the rifle to an acceptable (working) level and tested it. Here is a review.
This air rifle has a horrendous orange stock and weighs over 4 kg (heavy). It is a smooothbore 0.22. The construction seems good and sturdy. The trigger is made of brass

and it has a beautiful rear sight - fully adjustable and precise. It has a monster spring and a leather washer which was in good shape. The trigger unit is a separate self contained piece that comes off forst from the breech after which a single screw had to be removed to release the insanely compressed spring.
Cocking effort is ridiculously huge - combined with the fact that breaking the barrel itself (still tight) can dislocate a weak shoulder. Everything locks and unlocks with no loose parts, no rattling loose pieces. The trigger is tight and has no safety.
Accuracy can be summed up in one word. Bullshit.
This rifle appears to give good groupings at 10 meters except for one or two that go way waaay away. At 15 meters you get a "group" that is 8 inches across
But I can explain that with the most amazing photo I got. It is linked below. The image shows that the pellets are tumbling from the moment they leave the barrel. There was enough gunk left on the washer to give the pellets a light brown coating of muck and that much has left pellet shaped prints on the paper showing the exact tumbling position they hit the target. I have placed representative pellets next to the holes to illustrate the perfect match. Enjoy
I can't for the life of me understand how Indian manufacturers can palm off such crap on an unsuspecting public. There is no accountability. This rifle is junk and must never be boought by anyone who wants to shoot at any target smaller than a barn door. Unfortunately its seems that the average air rifle buyer has no clue of either what he wants or what he should be looking for. I score this rifle 2 on 10. It should really be called SISCO Target Misser, not Target Master.