I just cracked the small glass for my DWM Isolation tank and need a new one. I also need a set of orings. (Or the measurements of them so I can order them off Amazon)
You might try CarrackVape, they have the tall glass in stock but not the small. They don't list orings but they may have some. Canadian site but with DWM your options are pretty much limited to VaperzCloud and Carrack.
If you can source the sizes and wait a couple weeks, Fasttech has most sizes dirt cheap. Like $2-3 for 50 clear silicone. Post sizes when you get and I'll check what I have as I just ordered a bunch for my gear.