La Brea second look

 the NBC gave me a second look at the La Brea premier on Friday night. Now I clearly see wife Eve Harris lose her gold wedding ring at the distinctive boulder. The gold ring is recovered by her husband, Gavin Harris, who digs it up thousands of years later. Gold does not corrode easily. We know it is time travel.
What did I think the shiny object was that Eve left behind, the first time I saw it? It looked like a pull tab from a beer or soda can. Back in my ante-diluvial youth (shortly after La Brea), beer cans were made of steel lacquered on the inside to prevent rust.  Steel cans for other products were sometimes tin plated. We used a hand punch with a triangular beak to create twin holes to let air in and beer out on opposite sides of the can top. These punches were often referred to as 'church keys' to youthful inquirers. Then aluminum beer cans became the norm and the new way to open them was a ring attached to a teardrop tab embossed in the top of the can. One simply levered the ring up, pulled the tab sharply and left it where it dropped for the unwary to step on. There is a song about that happening in Margaritaville, I believe. It happened often enough the removable pull tabs were soon replaced by pull rings with the captive tabs we all use today. No reason to see such a relic in La Brea, but that is what the relic brain told me it was.
While discussing weapons any rescuers should bring with them, I neglected what the new visitors should do to protect themselves and their food from the dire wolves and other natives. Locking the food in a van or other vehicle will keep out the dire wolves (maybe not bears) and make it easier to guard. Rolling the vehicles into a circle will provide a sleeping/cooking area that is harder to overrun. 
Stan C. Smith would tell our visitors to use available straight or forked saplings to make wooden tipped spears. Stan writes the butt can be placed against the ground or tree trunk to fend off animals larger than ourselves.  Richard Currier asserts that carrying spears is the reason mankind learned to walk upright.
Bolas might be made with fist size rocks in fabric pockets. The ambulance may have suture needles or our Angelinos could use the sharp tips of agave leaves with the attached fibers for sewing. Capturing live animals with a bolas can create a meat surplus without refrigeration or may allow milking (after taming).
Water may be brought to camp with scavenged soda bottles. The water can be pasteurized in sunlight with an aluminum foil reflector (or boiled in a more heat resistant container).
The fact that La Brea lies in our past raises the possibility of contaminating our timeline with anachronistic material. I understand that roughly 1/3 of steel objects rust away in 100-years. The Titanic is likely to collapse in a few years. Stainless steel, titanium knees and hips, ceramic knees and hips, aluminum engine blocks and zirconium crowns might endure to the present day and create questions if found by gold rush prospectors.  I look forward to what the writers bring us next Tuesday.