I've lived my entire life in the US, and I distinctly remember at the age of about 7 or 8, reading the name as "Gruh Ham," only to be told that it's pronounced "Gram."
This recording is the first time I've heard someone else pronounce it as two syllables, but it may also be the first time I've ever heard the name pronounced by a non-US speaker.
I am American and have always pronounced it and heard it pronounced with two syllables. Maybe not as deliberately as the recording. I wonder if he is talking slowly as he is because it's so new to him, or maybe we're not hearing it at the right rate, or some combination thereof.
This is actually quite a Scottish accent, however it does not really fit with the stereotype (Groundskeeper Willy et al). To me (a Scot) it sounds very similar to George Galloway's accent: http://www.youtube.com/watch?v=V_AOTexf6uc
There are numerous distinct accents across Scotland despite it being a pretty tiny country.
I guess my expectation was that the older the recording, the goofier the accents would sound, due to changes over time. For example, the recordings of Edison have him sounding like no American alive today.
The Forvo website is interesting because it has some American (?) accents using the 2 syllable form, and some (Lindsey Graham) using the single syllable form.
(DuckDuckGo's search results were particularly useful for me here.)