The oiler which had been made for the 3″ Fowler compound steam engine looked OK, with a nice rounded brass cap, but despite various adjustments I could not induce it to work reliably. The pawls were very thin brass, not hardened steel, and the supporting bracket was very thin sheet steel which had little resistance to flexing.
I decided to replace the oiler. I could have made one from the engine plans, but when I saw some photos of these Foster Lincoln oilers on scale model traction engines, I decided to purchase.
The one which I purchased was designed for a 4″ scale traction engine, bigger than my 3″ Fowler, but the external dimensions were similar to those specified on the Fowler plans, and the Fowler is a 2 cylinder engine. So I decided to go “too big” than risk “too small”.
It arrived by mail today, from the U.K. Cost £116 + £10 p&p from “Live Steam Models”. Not cheap, but the quality appears to be excellent. Heavy brass body, hardened steel pawls and ratchet wheel, stainless steel water drain, and a powerful spring operated pump. The lid closes with good tight fit. Some filing will be required on a cut edge of the lid, but no big deal.