Chris,
Quelle is a catalog house similar to Sears in the US. Their products are made by various manufacturers including the B/S/H group, Electrolux, various Italian firms, etc.
They also market brand name goods such as Miele/LG, etc.
I know from my time working with B/S/H that they also can buy in sufficient quantity to have some products specially made to their standards.
Unfortunately, I can't find the 254 on their online website, so I can't try to narrow down the manufacturer for you.
But a quick search shows that the following manufacturers offer refrigerators in that area of economy (it is classed as A+ in Europe, 10% or better than class "A"):
Liebher
Haier
Bauknecht
EBD
Siemens
LG
MIELE
AEG
Since nearly all refrigerators in Europe are built by B/S/H or using parts from them (UK folks, let's not get into that one, again, ok?) you probably could find something along that line from them.
Haier doesn't have a particularly good name over here - but I have a two year old freezer from them which has been quiet and reliable from the beginning. Since I am often gone for several months at a stretch, this reliability is important to me.
EBD is a local German brand and I doubt you can get them.
LG has a horrible reputation in the US for bad service. Here in Germany their refrigerators are considered very good, if not the cheapest.
AEG belongs to the Electrolux group. Didn't someone have something nasty to say about them in a posting recently?
Miele - depending on whether you believe the UK crowd or someone who actually worked with B/S/H is mainly Bosch/Siemens, with some from Liebher. Which gets their parts from...well, never mind.
In short, you can get what you want from just about anyone.
However, if the 254 really floats your boat, post the exact catalog number or something more exact and I will toddle on down to their showroom here in Munich and find out for you.