from this sticky
https://www.gt-rider.com/thailand-motorcycle-forum/threads/25935-Chiang-Mai-Handy-Motorcycle-Related-Shops
4. SOMCHIT - DAENG GLON PRATU:
Aluminium welding & engineering. New exhausts, metal top boxes & cases, luggage racks. Two locations:
1. Daeng Glon Pra Tu
105 Rakaeng Rd
Chiang Mai
Tel: 053820784-6. Mobile: 0189508622
2. 2. Daeng Glon Pratu
250 Mahidon Road
Pa Daet
Tel: 053202269 & 053202270. Mobile 0896356908
Most if not all bike work is done at the "airport"location nowadays.
Note
That a number of board members have had him make up Touratech Zega & Jessie boxes copies.
However their aluminium is inferior as are their latches & seals.
Their pricing is not too dissimilar to the original, especially as there is now a professional Touratech dealer run by a passionate biker determined to give good service.
www.Touratech.co.th
Speak to K. Oam the manager or K. Peera the owner.
Whichever route you decide to go I would strongly recommend you get the TT steel mounting hoop
and the mounting pucks.
I have just gone down this route and found it was better to get the real thing.
Good luck and let us know how you get on.