Thanks Bob. I bit the bullet and bought them from Bert Flood, and they're sitting in my freezer now.
I assume when you talk about pulling them into place with bolts and spacer, the spacer is a large socket or similar with the bolt and washer going through it, into the threaded insert on the back of the flange and tighten the bolt?
Also assuming it'd be wise to buy separate M8 bolts for this process and not use the ones that are going on the prop?