Hello, though this is a pretty old thread I reply. Hope someone subscribed the follow ups.
I am researching since more than 20 years the Eissler families all over the world, and I do know this John Eissler (this is the original spelling) and his descendants in the USA. There is no connection to the Switzerland Isler.
If someone is interested please, do not hesitate to contact me by email:webmaster(at)eissler-pool.de or hgurski(at)aol.com