Here are a couple of old time gas welding books, great stuff of how it was done BTIG(before TIG)
They are from the internet archive and are downloadable in e book formats or PDF's or read online/full text.Oxy-acetylene welding manual
Covers welding of cast iron,steel,brass,and aluminum along with cutting. It may be going a little to far back 1919 and it is based on the army ordnance welding section. But still an interesting read.Oxy-acetylene welding and cutting : electric, forge and thermit welding, together with related methods and materials used in metal working and the oxygen process for removal of carbon
Has black smithing content
Printed in 1887, But the great thing about this book is it covers all the main forms of welding of the day. Which includes forge welding, both by fire and gas/forge welding. Thermit welding and then in CHAPTER VII Hand Forging and Welding: - Blacksmithing, Forging and Bending - Forge Welding Methods another source of how it was done back in the day.Oxy-acetylene welding practice; a practical presentation of the modern processes of welding, cutting, and lead burning, with special attention to welding technique for steel, cast iron, aluminum, copper and brass
Copyrighted in 1918 the sub title says it all historically interesting because of the welding by blow pipe (original torches) as it had only been practical since 1903. gives insight to the way it had to be done in the good old days.