Yes, that snap ring is readily available from McMaster Carr (in Stainless), but you may have to buy a bag (probably less than $10 for the bag) and shipping is always another $10...
Most of us remove the clip and never put it back. It really serves very little purpose... that is unless you have little kids that like to take things apart, like pens to see how they work... and they don't put things back together...
Here is a link to another thread that someone has some new snap rings (from Aqua Lung) in stock. Since you only need one the price is very reasonable (compared to buying a bag).
I was wondering if anyone knows where I can get yoke retaining rings for a Conshelf XIV 1st stage. I’ve seen plenty of sites selling the filter retaining rings but I haven’t found any of the larger yoke retaining rings. I’ve got a picture of the ring connected to the first stage. Any help would...
scubaboard.com
If you still have trouble getting one, let us know... like I said, there are a bunch of us, that must have a bunch of this snap rings that we have removed and they are stored somewhere...
Note: do not discourage your little kids from taking apart pens (and other non-dangerous items)... they may become engineers one day.