This Mares pneumatic gun looks in very good condition and appears to have had little use judging by the spear.
https://www.ebay.com/itm/MARES-FRONTIERSMAN-SPEAR-FISHING-GUN-SPEAR-ROD-CASE-26/153443431029?_trkparms=aid=888007&algo=DISC.MBE&ao=1&asc=20131227121020&meid=51d77a6e29304fffa439ef78da9d65fe&pid=100009&rk=1&rkt=1&sd=361970407596&itm=153443431029&_trksid=p2047675.c100009.m1982
The "Frontiersman" is the USA name for the "Medisten" or the 70 cm model. This gun is from the start of the plastic piston era and before the introduction of the Sten 87 "Competition Line" guns as once they were announced the old shape guns continued as the "Reef" model with blue tank barrels. The quality of the "Reef" guns was decreased to lower costs and they were not such great guns, although better than some other rubbish guns sold in those times.
https://www.ebay.com/itm/MARES-FRONTIERSMAN-SPEAR-FISHING-GUN-SPEAR-ROD-CASE-26/153443431029?_trkparms=aid=888007&algo=DISC.MBE&ao=1&asc=20131227121020&meid=51d77a6e29304fffa439ef78da9d65fe&pid=100009&rk=1&rkt=1&sd=361970407596&itm=153443431029&_trksid=p2047675.c100009.m1982
The "Frontiersman" is the USA name for the "Medisten" or the 70 cm model. This gun is from the start of the plastic piston era and before the introduction of the Sten 87 "Competition Line" guns as once they were announced the old shape guns continued as the "Reef" model with blue tank barrels. The quality of the "Reef" guns was decreased to lower costs and they were not such great guns, although better than some other rubbish guns sold in those times.