I forgot I already took some pictures. Here they are:
Get some 3/4 x 3/4 x 1/8 aluminum angle (Lowes, Home Depot); cut two pieces 6 inches long.
Mark a 3/4 x 3/4 cutout on one side of the angle, and cut it out (this makes it possible to bend the aluminum 90 degrees)
Put the aluminum in a vise at the point of the cutout you made, and bend the intact side of the aluminum 90 degrees by gently and slowly pounding on the aluminum with a hammer in the direction of the desired bend.
In the side of the bracket that will be attached to the floor, drill two holes on each leg of the bracket. On one side of the bracket that will touch the side of the legs, drill one hole.
Carefully file off any rough aluminum. Paint with your desired color. I used 3/4 inch long screws to attach the bracket to the floor. Be sure to check the thickness of your floor, especially if you will be attaching the brackets to the floor of a slide. First mark with masking tape where, exactly and carefully, the legs of the sofa are. Move the sofa to get access, and place the brackets carefully where you marked the legs are. Attach with screws. Return the sofa to its place - hopefully the brackets are in the correct place. Use one screw to attach each bracket to it's leg.
Hope this helps.
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch