The 17½" did not come with a finder. For a few months I used a hex bolt at the top end of the tube as a finder, but this was not the most accurate finder!
So, I have added two finders: a Tel-Rad and a Celestron 6x30mm straight-through finder. I know many people prefer bigger finders — in the 80-100mm range — but not me (I still use a 6x30mm finder on my C8 too). The Tel-Rad is highly recommended — even if you have a finderscope.
The Tel-Rad (at rear) and 6x30mm finder (mounted on the block of wood).
The wires are for my Kendrick dew remover.
Note the proximity of the finders and eyepiece. I found this to be the best ergonomic layout for me. The block of wood serves to raise the finder away from the tube so it's easier to look through. A primitive mounting system to be sure, but it has worked fine for almost 10 years, and cost nothing to make!
As it happens, my C8 and my 17½" have roughly the same focal length (8" f/10 vs. 17½" f/4.5), so all the eyepiece magnifications work out the same! With the same finderscope on both instruments, I am really standardized!