Thanks to Melodi Hackett of Maine and everyone on the yahoogroups weaving email list who answered my questions in the previous post!
The large silver thing in the first photo indeed is used with the black handle. It's used to push down a lamm while you are setting the tie-up. The smaller of the pins (in the photo with the silver bar) is used to hook the black handle in the down position so that you can use both hands for the tie-up process. Here's what it looks like:
The spring-string-chain found at the back of the loom near the warp beam is to act as a brake when the ratchet system is released for advancing the warp. Without it, the warp beam will spin like the dickens once tension is released. I'm really glad I found out about this before starting my first project.
The first project is in progress! I measured out the warp and have it sleyed in the reed. I spent time last night moving the heddles and will finish dressing the loom today. I'm going to take a stab at that reversible rag rug in the latest Handwoven magazine. It only requires 4 harnesses in a straight draw but the simplicity will allow me to become familiar with this new loom. I can tackle an 8 harness project next time!