This small pump was designed for use in RC combat model warships, but I am also using it in an automated garden watering system, and I expect there are many other uses for a small pump.  I used stainless steel hardware, it's not that much more expensive, and is in line with its design purpose of getting submerged in fresh water regularly.   The pump itself will work fine in salt water, but the motor will short out due to Na and Cl ions in the water.   Some fettling may be needed around the rim of the impeller for it to fit into the pump;  this is a WIP and I am tweaking the impeller size in the future so that it fits well with minimal fettling.  Additionally, the recess for the brass collar in the impeller should be cleaned up with a drill bit prior to using an ABS/acetone slurry to weld the collar to the impeller.  Strongly recommend putting the collar in without the set screw, then drilling (I use a drill bit held in my hand, not a power drill) in from the side to access the set screw hole.  The brass tube should be inserted into the discharge hole and secured there with either slurry or CA glue.