@ 5 lbs
That depends on the exact model of rifle.
Depends on exactly which rifle(s) you refer to.
.58-1.00
9+ pounds.
14 lbs
The "Daisy Cutter" bomb weighs 15,000 pounds.
Check the weight. Copper pennies (pre-1982) should weigh 3.11 grams.
About 7.5 lbs.
That depends on the kind of car it's a replica of. A Matchbox fire engine will weigh more than a Miata.
It depends on which rifle. <><><> Agree with above. There is no one "assault rifle", and no one weight. The German StG44 weighed 10.2 lbs, the M16 weighs 7.1 lbs.
The best way to have this rifle repaired is to do a wed search for "Air Gun repair" and locate someone near you to have it repaired. There are several people/locations around the world who repair airguns for a living. I've sent out several from my collection to shops in California and had them restored or repaired. a model 250 ( Milbro) at best is worth $130. At least is worth $25 so you have to weigh the value of the rifle verses the cost of repair.
roughly one pound, when loaded