I saw fingers on
ebay for $56 + 12 S&H for 125 of them
ebay plucker finger linkey
You can get large pullys from an HVAC company - especially out here in AZ where swamp coolers are big
The plate can be made from aluminum or Thick plastic - If you go on the
Whizbang site he explains that the originals are made of plastic. Holes as stated are 3/4" and counterbored in the thicker plastic or counter sunk in the aluminum to make pulling them through easier.
I've not seen this said but if you put a bit of oil (mineral I think would work best / not rot / is food safe) it will make pulling the fingers through IMMENSE-LY easier. I watched several assembly videos and it took most folks 20 - 30 seconds with a large pair of channel locks. A small drop of mineral oil would shorten that to a few seconds.
Don't cut the entire bottom of the barrel out. Just cut a small/medium slot in the bottom or edge to which you can mount a trough & bucket. Drill a bunch of holes in the bucket fo rthe water to drain through. It will be much easier to empty a bucket than rake up a 360 degree spray of feathers.
Flip two or three fingers upside down so they are pointing down and just missing the bottom of the barrel. This will help evacuate/clean the bottom out as it rotates.
You do not need a solid shaft, A shaft from a swamp cooler is hollow and they sell sleeved (not bearings, bronze bushings) pillow blocks that slip right on for Cheep. They will not last as long as the expensive bearings but they have built in oil cups and should be fine for occasional home use. If you are planning on processing 1000's of birds - go with the bearings.
Hope it helps