I've been ordering from PBR since 2001. At least 6 orders per year. I've only had ONE issue with them - a package that went missing for 3 months and then ended up at my address full of coffee beans - but no parts missing.
If RTBB does not have the parts, then PBR are the next best bet. I'm now using a "wire transfer" that costs $20 and takes 5 minutes. Fantastic !