The guy you got it from, surely he has some extra hose? ...and you'll be sure to get the correct diameter too!
This is probably the biggest downside in these china RTR models, in an European kit requiring assembly, there is always extra little bits like nuts & bolts & hose left after assembly.
No worries about bleeding air from double acting cylinders, you have pressure on both sides of piston to squeeze the air out. A single acting cyl however, as in a telescoping trk hoist from wdc or SA, there is a procedure to follow to get the air out so the cyl extends & retracts smoothly.