Royal Alloy GP - Broken Back Rest (Rear Rack) Welds

Royal Alloy GP 300 Broken Back Rest Welds causing an unstable and loose back rest. Removed, welded and refitted. Fitting the back rest (rear folding rack) is just 4 bolts. (This could be a "How to" video on fitting it.) This appears to be a common problem! Is it poor workmanship ( I think so in this case) or poor fitting - over tightening? DISCLAIMER I am not a professional and as such will not be responsible for property damage or injury incurred as a result of any of the information contained in these videos. They are to give information only and carried out with the best of my limited ability. Also, information given in these videos does not guarantee the desired outcome. Always refer to the vehicle handbook and/or service manual for specific settings and procedures for your own vehicle.