Cowl / Engine Plugs for 1964 C172 Skyhawk - Any Recommendations ???

Hello group,

Yup, bird problems !!! My homemade cowl plugs are not doing the job
anymore, so I need to fork out some dough and get me a commercial set. I
know of ones from Bruce's Custom Covers and Kennon; are there others ? Of
these, which are the best for MY type of engine intake (remember that this
year Skyhawk has One Large Oval Openning, with only the Prop Shaft as a
seaparator...

Any help appreciated.

Regards,

Philip