I have a bunch of wing screws I am selling. Most are Slingy "style" but I'm sure more than Slingerland used these kind of wing screws.

I think some are Gibraltar aftermarkets. They have lathe marks on the top. Some are exactly like my 1964 Slingy set with a round top and a little flat spot.

Some are more cylindrical and have a flat top. I sell a ton of stuff on eBay and I try not to represent anything.

Here are the 2 auctions I listed so far ...

http://www.ebay.com/itm/321646294195?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649

http://www.ebay.com/itm/221667183233?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649

I am pretty sure the first link is OEM Slingy.

I am also pretty sure the second link is Gibraltar.

Here are a couple pictures of the entire lot.

Thanks for the help.