If the front cover on your transmission has the threads stripped for the bolt that secures the lever, here is an easy fix. No need to buy a $100++ replacement plate from your favorite parts house.
Please read all the way through before proceeding with the fix.
It can be done with the front cover mounted to the transmission.
Go to your local hardware store and buy a 5/16” fine thread bolt 2” long. The un-threaded section (the barrel) should be about 1” long. Get two 5/16” fine thread nuts.
The following pictures do not show the lever installed. With the lever installed it is just as easy.
If the threads are completely stripped, you can push the replacement bolt all the way through. It looks long but will clear the bellhousing. If the threads are partially stripped, thread the new bolt in all the way so that only the barrel is showing. See picture one.

Install a nut on the bolt and tighten it gently, about 35 inch pounds. The bolt/nut arrangement is much stronger than the bolt into the aluminum threads and it is easy to over-tighten and bend the arms on the plate. If you see or feel the lever tightening up, back off about an eighth of a turn.
Install a second nut and snug it up to the first one. Using two wrenches, squeeze the two nuts together, creating a locknut. Use Locktite Blue for added insurance. See pictures two and three.
If you have an original locking washer, put it on before you install the bolt. This keeps the bolt from rotating in the holes.
If you don’t have one, you can make one quickly and easily.
I used a piece of 22g sheet steel. I bored a 5/16” hole in it and trimmed it to fit so that the bottom touches the raised area just below the bolt hole. The other sides are free hand. See picture four.
After you havesqueezed the locknut onto the first nut, use a small hammer and punch to bend part of the locking washer tab over one the flats on the head of the bolt. This will keep the bolt from rotating and fretting out the hole in the aluminum plate. See picture five.
Not terribly elegant, but it works!