CLM-620002
A New Replacement Auger Rubber Paddle / Scraper Kit for 3hp-4.5HP 2 cycle MTD Yard Machines 21" Snowblowers.

This kit is designed to replace 2005 Model and Older machines.

MTD753-0613
MTD731-1033

The large rubber is held on by 5 bolts and 1 rivet.  You'd replace the rivet with a self tapping screw.
Take note of the bolt hole pattern to verify that it's correct for your machine.