Sarabela,
The lights sold by Sew-Classic and such are good useable replacements, but are nowhere near as nice as the originals.
My early 66s take this light fixture: {
http://www.shop.sew-classic.com/Sing...nes-SCE428.htm }.
Depending on whether or not the machine has it's original motor will depend on how you wire it in. It goes under the inspection plate and is held on by the plate screw.
My later 66s have a notch at the 3 O'clock position under the inspection plate, they can use this light fixture:
{
http://www.shop.sew-classic.com/Ligh...ack-SCE503.htm } or the one above.
This one comes with and without a plug so it can be purchased for aftermarket type wiring or the original motor style.
S-C also has the screw to attach it if you go this route.
The early machines do not have a quick release for the bobbin case but they do have a hole on the side of the bobbin case retainer for the spring and felt wick.
The later machines have a quick release for the bobbin case and also have the hole for the spring and wick. I think your machine will be one with the QR. The hole is probably covered with gunk.
Here is a site that gives super duper instructions on how to R&R, clean, fix, make a new wick, and adjust the bobbin areas on all 66s: {
http://www.tfsr.org/publications/tec...machine_manual }.
This one you should bookmark.
In lieu of the wick just put a drop of oil under the bobbin case where it rides on the hook occasionally.
Joe