Streak marks inside glass

maybe from being shook up enough that the spring scrapey scrapeyed the walls? or perhaps somebody customized the inside in the past and didn't clean the walls very good.

My old wizard lamp had that. I noticed it after it sat in storage for a few years. It eventually went away. After normal operating times. Just be patient with the lamps. Took about a month or more to go away for me.

looks great. what is the size of that lava lamp ?

Not sure of the reason behind it but a handful of mine have this and I HATE it. I ended up draining the fluid aside and scrubbed the interior with a brush, it was a wonderful fix.