I thought I'll start off with a few manufactures and how to identify them. One of, if not the largest blow torch manufacturer in the U.S. was Clayton & Lambert.
I have many of these from early models to quite resent.
A little history:
Clayton & Lambert Mfg. Co.
In 1882 three brothers named Lambert started a venture in Ypsilanti, MI for the manufacture of gasoline fuelled blow torches.
Mechanics found the intense portable heat of these torches very useful, word soon spread and demand grew, the business flourished.
In 1887, a patented firepot for melting lead was added to the torch line, and its inventor, a Mr Lambert was taken into partnership.
By 1889, demand for blow torches increased beyond production capacity and the company moved to a larger site in Detroit.
There were a few other moves after this the last being large plant at Buckner KY.
In 1970 C&L discontinued the production of gasoline blow torches; they had become extinct due to the use of propane.

This is a fairly typical C&L torch, this one I have restored to working condition. Yes I do use it in my shop at times. C&L logo is still visible.

Most C&L torches have the shield stamped into the tank. Older models did not have this.

Again
most C&L torches will have the model number stamped on the top handle support. This one's a No. 327 (c1952)

Just out of interest, the hook on top of blow torches was to hold a copper soldering iron not to hang up the torch.
Batz