Well, I have a Michaels in walking distance but Hastings Plastics in Santa Monica is where I've been buying resin and other stuff.
By doing a google search I found that there was another S&W Plastic (same company) in Montclair. That's a doable drive.
Today I found that one of the plants manufacturing Silmar 41 is in Hawthorne (about 12 miles from me) but I can't find a local distributor or retailer of the gallons. Oh well, the cost of driving is still cheaper than the shipping costs.... for now.