Triangular grip ballpoint by Unipeco (Union Pen&Pencil Co., New York), circa...no exact idea. 1950s-1970s. Another go-to, mostly because it's in my favorite color (British racing green) and it's got an excellent grip due to the tapered triangular design. Super-lightweight yet substantial feeling. Takes current plastic barrel refills, though I had to ream the metal tip a bit. I have a few from this company and they did some unique designs. Apologies for the slightly low res.
Telstar black ballpoint. U.S. made, 1960s I assume, have found nothing about this company. https://ibb.co/KGr8YWw https://ibb.co/DYtK9jx Same basic look as Skillcraft military issue pens but wider. Metal tip is always a nice touch. Takes modern refills.
Knight Riter all metal ballpoint, 1973, part of a complete salesman's case of samples I was recently given. Very nice quality, finely ribbed knurling gives excellent grip. Accepted a modern refill with slight reaming.
UNIPECO, Yonkers, NY. Clear barrel with the paper advertising insert removed. Accepts modern fine tip refills.
This thread got me thinking about the once ubiquitous advertising wall or desk calendar. I recall the ones offered by car body shops were not too family friendly
Unknown maker, U.S. made. Satin brushed steel, likely a loose copy of the classic Parker Jotter but less hefty and not as precisely machined (slight misalignment between upper and lower when screwed tight). Writes well anyway. Accepts fine tip Papermate cartridge refills.
Ritepoint USA, nickel plated, thin barrel with nice no slip texturing. Gives a better grip and weighs less than a comparable Jotter. The only old pen I have that has a working original refill.