There is a public tree on ancestry which has 3 records of England Alien Arrivals for Casper.
23 May 1837
22 April 1838
17 May 1840
The last record shows him arriving wth a group of musicians including a Heinrich Lemmer. There are two Henry Lemmer born Germany on the 1871 census. Otherwise I can find nothing that you will not already have. The 1881 census, the baptisms of Casper and Alice's sons Casper and Carl Printz, the birth and death of son Ludovic William, and the birth of daughter Alice.
Do you have the marriage certificates for Casper to Charlotte Butt and Alice? They could give his father's name and witnesses etc which may help.