I have one timing belt re-installation under my belt.

No doubt like you, I am wondering whether your timing belt slipped. It sounds
like you're wondering if the key is somehow not holding the crankshaft TB pulley
securely, too.

FWIW: I googled and saw a post that said one timing belt tooth off = 19 degrees
of crank timing. The middle mark of the three marks is 18 degrees from TDC.
Seems like this is coincident enough with your finding today to suggest your
belt is off by one tooth.

Barring other suggestions from those who have more timing belt installations
under their belt, I'd do a full timing belt re-installation. This would allow me
to examine the crankshaft TB pulley key, maybe the camshaft TB pulley key, and
the tensioner. If anything looks at all out of sorts, I'd replace the timing
belt, the tensioner, and the tensioner spring.

Given that you don't know how old the timing belt is anyway, replacement might
be a very good idea.

I've read of people checking the piston's position by sticking a rod down the
spark plug hole. If you don't want to do a full timing belt re-installation, I'd
sure do this.

Nice progress, BTW.

"Chopface" <thename_is_slick@yahoo.com> wrote
> I decided to see if I could slip the belt off of the camshaft pulley
> with the crankshaft lined up at TDC. It looks doable and I have a socket
> wrench combo that can get at the tensioner bolt to redo the tension
> according to my Helm manual once the belt is back on.
>
> Does anyone have enough experience based on what I've shared in these
> three posts to judge that the crankshaft pulley was put back on properly
> with the key in when whoever screwed this all up? With the crankshaft
> pulley at TDC, the camshaft pulley now has the up mark facing downward,
> about 5:00, and a marked line on the camshaft pulley on the opposite
> side of the pulley from the plastic pointer is approximately lined up
> with the pointer.
>
> I am very tempted to try to fix this, but think I should probably wait
> to see if I can trust that the #1 piston is truly TDC when the
> crankshaft pulley mark is ligned up for TDC. Should i stick something
> down the spark plug hole?