I have a pair on my car and recommend them. My 5-louvers were acquired from another Clubbie years ago, but there are two sources for new ones. MSA will send you two inspection lids with 4 wide louvers each, if you send them "X" amount of $ and two of your own inspection lids which they can use in future orders. In other words, you probably don't get your own lids back; yours will get cleaned up, louvered, then sold to a future buyer.
The original 5-louver lids which were offered by Datsun during the 1970s occasionally appear on eBay. (They are rumored to have been first invented by Brian Marrow while he was creating his prototype Scarab V8 240Z).
Really good to hear you in here again.
Frank T