I have used these and they work perfectly ok, you will need to remover your original cut key from your old worn out front case, hot boiling in a bowl helps, once out you can remove the cotter pin, same for the new front case, then insert your cut key.
Clip your old back with the transponder in to the new front case, job done.
https://www.ebay.co.uk/itm/Replaceme...72.m2749.l2649