Are you serious ?
You might want to reconsider .
If you are, best wishes.
FYI, I happened to see that Ryan has a FB page which says this, in the "Work" field:
VVS, Inc. Canteen
Service Technician · October 23, 2017 to present · Lincoln, Nebraska
So, I suspect that the pool cue making business will be part-time, which makes sense and is very understandable.
In my view, Ryan is better served choosing a new name to represent his cues now that he is sperated from Muehler.
His work and reputation speaks for itself do there is no harm to his future sales if he makes the name change now so there is no confusion who he is compared to his former employer.
Branding is a very important aspect in presenting your company to the public. I have always thought Rat was a bad name to represent a custom cue. The name has many negative connotations in the vernacular. Although Ryan's skills and reputation are associated with Rat, many of his future sales will have to be created from selling to new people that may not understand The history. Ryan Cues for example, would be much better than Rat. IMO
A new name with 100% positive imagery will definitely make a difference downstream and will remove any confusion with Muehler.
Branding your company's name and targeting your nitch in the market is something that should be carefully considered.
Good luck to Ryan and his family considering his new business venture.