Chris,
don't get me wrong please. I just noticed while I was watching your video on You-Tube that your pronounciation of Glöckler is partly wrong. The reason might be that the german language have different posibilities with some vocals : - a -, -o-, and - u -. They could be written > ä ; ö and ü, ( correctly written as an - ae -, oe and - ue- if you don't
have a chance to put quotation marks above the -ä-, -ö- and -ü- at the end ).
The name of the man from Frankfurt was Walter Gl-
Ö-ckler ( not like you say Gl -"O"-ckler ) ( just an example: you may know the famous german fabrik MÄRKLIN. If you will be correct, don't wright down Marklin, Maerklin would be right way.
I didn't found an english word for it but an exellent example is the first syllable of the french word "œuvre" = oeuvre >
http://www.youtube.com/watch?v=eVsXNLg87mo
If you will spent some time on the theme "Glöckers cars" on YouTube you will find this
http://www.youtube.com/watch?v=gU7M9eN_8Ss ( language is nederlands ) and a video on the 550:
http://www.youtube.com/watch?v=HNRJneoTtPc ( at 0.45 sec. the ever grinding guy says Glöckler in the right way as our euroupean neighbour does it too ! ). In my opinion, if you had spent such a long time with a tremendous result you should use the right pronounciation.
all the best