Do signature weapons ever become free

I found a tower weapon unlock list here:

Radio Towers reward you with free weapons and items and they also unlock nearby Supply Drop missions. You’re rewarded with free weapons based on the amount of Radio Towers you’ve unlocked, not by the specific Radio Tower itself. This means that if you want a specific weapon, you can just go for the quickest/easiest route to get there, without having to do a specific tower the other side of the map. The below weapons have been placed into categories along with how many Radio Towers you need to get them for free.

Handguns

• 1911

• 6P9

• .44 Magnum – Requires 11 Radio Tower unlocks.

• D50 – Requires 12 Radio Tower unlocks.

SMGs

• Skorpion – Requires 2 Radio Tower unlocks.

• A2000 – Requires 5 Radio Tower unlocks.

• MP5 – Requires 9 Radio Tower unlocks.

• BZ19 – Requires 14 Radio Tower unlocks.

• Vector .45 ACP – Requires 12 Radio Tower unlocks.

Shotguns

• M133 – Requires 5 Radio Tower unlocks.

• 1887 – Requires 4 Radio Tower unlocks.

• SPAS-12 – Requires 13 Radio Tower unlocks.

Assault Rifles

• AK47 – Requires 2 Radio Tower unlocks.

• STG-90

• F1 – Requires 8 Radio Tower unlocks.

• MS16 – Requires 10 Radio Tower unlocks.

• P416 – Requires 15 Radio Tower unlocks.

• ACE – Requires 13 Radio Tower unlocks.

• Bushman – Signature Weapon. Requires 18 Radio Tower Unlocks

Sniper Rifles

• SVD – Requires 3 Radio Tower unlocks.

• M-700 – Requires 6 Radio Tower unlocks.

• Z93 – Requires 15 Radio Tower unlocks.

LMG’s

• PKM – Requires 4 Radio Tower unlocks.

• U100 – Requires 7 Radio Tower unlocks.

• MKG – Requires 14 Radio Tower unlocks.

Launchers

• RPG-7 – Requires 6 Radio Tower unlocks.

• GL-94 – Requires 8 Radio Tower unlocks.

Specials - Repair Tool – Requires 2 Radio Tower unlocks.

• Flare Gun – Requires 7 Radio Tower unlocks.

• Recurve Bow – Requires 3 Radio Tower unlocks.

• Flamethrower – Requires 5 Radio Tower unlocks.

I've played the game and looked through the wiki, there is no use that I've seen for the miscellaneous items that you gather from loot chests and dead bodies. The names for everything is just filler, make the player feel a sense of pride when he picks up a Diamond or Smartphone. The only quest items you will gather would be herbs and leather, occasionally some other item that you can only get while performing the quest.