Here's a hubmotor that I found with a quick Google search, that appears to be very similar to yours:
Company Name:Yongkang Success Permanent Magnetic Motor Manufactory
Contact person:Ms. Susan Wu
Address:No. 16, Xinxin Road, Huanggang Industrial Zone, Yongkang City, Jinhua, Zhejiang, China
Mobile phone:86-579-87114545
Telephone:86-579-87114545
Web Site:www.yksx.cn
I suspect your motor was probably manufactured by the above company, but I'll let you contact them direct if you want to try and confirm it.
AlanP.S. I'd be very surprised if it could actually climb a
40 degree slope!