Viperdoc writes:

Why would you fly 12 miles from the VOR and then turn around to go back out
and intercept the 19 DME arc? V187 does not appear to be depicted on the
approach plate. What was the IAF?

I was already inside the 19 DME arc while I was still trying to figure out
what to do next. The MSA was 4300, and I saw that the arc was 4000, so I flew
back out to the arc to descend to 4000, since I figured terrain clearance
would be guaranteed along the arc but not elsewhere.

I saw three IAFs, one at the PEN NDB, and two at either end of the DME arc. I
wasn't sure if I was supposed to go all the way to the IAF at the end of the
arc to use it.

V187 isn't marked on approach plates. It's on the en-route charts and
sectionals. AST is on the airway, and I was coming from OLM, also on the
airway.

Your best answer to this question would be to get a PPL, and then and IR
with a competent instructor, who could easily answer the questions.

That would be tremendous overkill, extremely time-consuming and expensive. I
was hoping someone here would be able to help. It's a bit like suggesting
that one become a surgeon in order to learn the effects of aspirin.