Just my opinion, but deviating from the 10" requirement for mound height is like changing the distance between your bases...just not kosher. So, if you haven't already, make contact with someone in your area who does excavation/dirt hauling. They will have the equipment "shoot" your mound height (to give your mound building a starting point), the clay you need, and will often donate both I've found out. Great for a limited budget.
If you are indeed limited, you can build a fine mound with good, clean red clay and without the bricks. It's just gonna require more work daily to repair the wear holes. Just have to decide which is the lesser of two evils, I guess.
You said you have the msrmnts. so I only have two suggestions (after finding the excavator):
1) Use your players! It goes much faster when a well supervised work force of a dozen gets after it as opposed to you going at it solo. "Alright boys, the slope is good here. Tamp it!".
2) Build a 2x4 box/frame to frame up the flat plateau that makes up the top of the mound and then work off of that for the slope. When we rebuild, we place the 3'x5' frame in the correct location, making sure its level. We then add clay and tamp until the plateau is completed. Carefully remove the frame and work the clay around (like working concrete with a long 2x4) and roll/tamp until the slope is correct. We place an old home plate or rubber mat between the 2x4 and plateau to keep from destroying the edges we got witht the frame. We continue around the mound until completed.