ANSWER: For those looking for replacement C-Clips, I bought this kit from Amazon (could source from other locations) https://www.amazon.com/dp/B095Y3M9LC

After review, the largest clip is 3mm outer diameter (O.D), 1.00mm inner diameter (I.D.) with a height of 0.2mm. So, if you have buttons and lost the clips, you can replace pretty easily.