There are some inexpensive replica M84 scope/mount combos that can be had for around $450. To find a real USGI M84 scope and mount your going to have to spend around $1500-$2000 these days. It's getting tough to find them, too. The genuine cone flash hiders aren't worth the money or effort to find so you can skip that piece. You really don't want to shoot with it installed, anyway. It does look neat, though. Get a reproduction or later production USGI cheek rest. The originals are hard to come by, expensive, and often not in great shape.
Everything else will come from a regular M1 Garand, I suppose. I assume you are starting with a regular M1 Garand rifle?
I was lucky to get one of the 'lottery' M1D rifles new in the box from the DCM. They auctioned some off back in 1996 (purchase price $650!).
Here's what the original cheek pad looked like...new and un-used by ruined from the eyelet corrosion. It destroys the leather and it's unusable. Later, they coated or treated the eyelets to prevent this, I suppose. Don't buy one that has verdigris around the eyelets!
Original:
I found a new old stock USGI cheek pad from 1976 that was in good useable condition.
Later production:
There were two tiny pre-drilled holes in the bottom of the original M1D stock for the brass screws that came with the original cheek rest. when you use the original screw positions, it forces the cheek rest into a position to act as both an offset and a slight riser.
