1960s? Vintage scuba: Nemrod Comando pneumatic spear gun, SOS depth guage + misc

Going through my dads closet and found his old spear gun and what Im guessing is a tank valve fitting and depth gauge

The speargun has been sitting in storage for over 30 years. To my untrained eye, it appears in excellent condition even down the the "comando" sticker. I pumped it up to get a little pressure and it ejects the spear. It is currently charged to confirm it holds the air. It has some of the other pieces that go along with the gun, but Im not sure what they're for.

I didn't see any markings in the chrome of the tank fitting. It is also from the 60s? when my dad was diving. I actually don't know what it is exactly.

SOS oil filled depth gauge. Made in Italy. 5ft increments up to 325Ft. Looks mint. The plastic case that it came in is included but is cracked.

I don't know that value of these items. Open to offers. email teddy1976@hotmail.com for pictures. Located in Delta BC, Canada. Thx.

the speargun seems to intermitently seep air from the trigger area as some oil residue came out. Other than this spot, it seems to hold air fine.

The tank valve unit threads onto the charging area of the gun, leading me to believe it is a way to charge up the speargun without using the hand pump (it was packed away with the gun and pump)

Any other questions please ask. Thx.