I’ve only ever had one blaster worked on by a tech and that was my first one, worked on every other blaster myself being mostly successful in the end, sometimes took a few goes but got there, all learning experiences.
I’ve seen a number of breakdown videos for it and the biggest hurdles were some springs that aren’t captive that fall out when taking the outer shell off. If it’s just an o-ring/seal needing replacing I should be able to figure it out, otherwise if something has broken I’m up the creek…
Just had a look and the o-ring kit I saw was for the GBBR’s.