This combination of very thin brass a very conductive material to a strong, resistive stainless material is very difficult. The brass due to its conductivity will be slow to heat up. The stainless will heat up and probably conduct heat into the brass. Since the brass is so thin it will suddenly overheat and melt through.
If any, there is a very small window for success.
A micro-welder must be used. I would suggest trying resistance brazing or soldering. Obtain an appropriate braze or solder alloy compatible with both materials. It must have a melting point below the brass and sufficient bonding strength for the application. A fluz may be necessary. Heat just enough to melt the joint material and only have adequate force to hold the parts in place. Don’t force the braze alloy out of the joint. Maintain force until the joint material solidifies.
References:
RWMA Resistance Welding Manual 4th Edition