A patent search was done for the lid designs.
It was found that there are no exact patents on the unique lid designs.
The closest patent may be this one below (an expired German patent) that shows a somewhat similar dispenser concept on a completely different product (not a salt/pepper shaker).
https://worldwide.espacenet.com/patent/search?q=pn%3DDE102011104738A1The rest of the patents are less relevant.
https://pdfpiw.uspto.gov/.piw?Docid=02618404Based on the above, there seems to be a gap in the IP landscape for where we want to enter the market with this creation. It would be possible to sell our inventions and even apply for our own patents.