I still have to break the edges, but it looks good. I had to buy some 10/24 lock nuts for the spacers, total expenditure of a buck and a half. You can see what I did with those. As it turns out, there is just enough give in them when I tightened the bolts so that the filter element is nice and snug (I got lucky!)
One of the bolts is too long and another is flat blade screwdrive rather than phillips. Big deal, I put them on the bottom where they can't be seen