My 80s Nishiki Cresta is missing the part that fits into the rear wheel dropout that rests against the axle. Does anyone know that name of this part and where I could find one?

Time travel...or maybe ebay!

Thanks guys! Now I know what to learn for when searching for one. Time travel might be tough but I can definitely do eBay

I have a set of those, in case the OP is interested he or she can send me a PM.

https://www.ebay.com/sch/i.html?_fro...pacer&_sacat=0

Thanks guys.
[MENTION=84826]randyjawa[/MENTION] - Thanks. I appreciate your willingness to help out. I did go straight to ebay, however, and found one there. Have a grea Labor Day!
[MENTION=22396]Wildwood[/MENTION] - It never occurred to me that a drop spacer is usually used for just the drive side. I actually thought one was missing from my bike
[MENTION=28167]dedhed[/MENTION] - Thanks. I managed to find that same list of items on eBay and went for one that was $9.99 plus shipping. Hopefully the wheel will line up correctly using it on the non-drive side.

Ritchie Logic-
I've got one that looks exactly like what you posted. If your other solutions don't work out, PM me and I'll mail it to you.

I thought they were more commonly used on the NDS side with claw derailleur hangers on the DS side.

I didn't realize they were used with forged droputs, no adjustment screws, and an integral derailleur hanger.

A matched pair would be best.

Make sure the wheel is properly dished, stays are straight, dropouts are aligned, then you can do fine tuning by filing if you wish.

I think it is unrealistic to expect the wheel to sit straight even when two identical axle stops are used.

These things were normally used on one side, which served to position the axle front-to-rear (mainly with respect to proper chain length vs. tension in use).

Standing behind the bike just before closing the QR lever with the left hand, one first applies a little weight to the saddle with the right hand, while using their knee to "aim" the tire equally between the chainstays.

Weight applied to the saddle (or stem) while securing the QR lever is always a good idea when installing the rear or front wheel, respectively. Especially in the rear, where mere chain tension may impede the axle settling fully into a vertical dropout when the bike is relatively light.

Using two of these axle stops (or just one in conjunction with a derailer claw), one may have to use a round file to trim the working end of the axle stop. This is to fine-tune the exact centering of the tire between the dropouts, since these stops don't have any fine-adjustment mechanism such as offered by threaded adjusters. So I kind of prefer to use only a single axle stop, and just use my knee to center the tire as I flip the QR lever.