Not sure how a spider would be used on a paint can lid. A biscuit bridge perhaps, but a traditional resonator spider uses a center screw to touch the spider and resonator cone thus transferring sound from the bridge on the spider to the cone. Not sure how that setup would be done with a paint can. Do you have a photo?
Thanks for the photo.
I have to admit that I have never seen that before. It is definitely a cool looking rig. Hopefully, someone on the site has seen it before and knows the source.
Good luck (for both of us).
Stewmac sell a couple of different sizes, pretty sure Gitty has smaller ones also, Old Lowe used to sell them as well, or try e bay...https://www.google.com.au/search?q=resonator+guitar+spider+e+bay&am...
I checked Gitty and found no spiders. The interesting thing about the spider in the photo is that it only has six arms (full sized spiders have eight). It also looks purpose built and not a modification of some other type of casting.
The photo came from the Gitty Paint Can Lid Contest. I'm trying to email the guy that built the entry with the spider to see if he knows where they can be found.
I've seen one here on CBN, but it was custom made by the builder. Can't remember who the builder was.
The usual spider-bridges are 9&1/4" diameter, but they can be trimmed back a couple inches. However, the largest paint lids have a 5" area for the bridge. Don't think you could cut a regular one back far enough.
I found a old non-working turntable and removed the aluminum piece that holds the record. It's made just like a spider bridge. It's 11&5/8", but could be cut back to 7". Maybe not helpful for this application, but might be of use later or to someone else.
Could use a alternator housing too. They look just like that and come in many sizes. Get one from a junk/salvage yard.