Turns out the Bilstein website, hence most dealers, have the part numbers incorrect. Here are the correct part numbers according to the Bilstein USA representative I spoke to. These are for 463 chassis from 2002 on. Both the G and the AMG takes the same models. (Don't order the cheaper B4 Heavy Duty Suspension models unless your G is an armored version!)

The good news is that these are high pressure mono-tube shocks like the B6 HD shocks with a similar damping curve.

Front:
46mm Monotube Shock Absorber

New Part Number (24-017275)
MSRP: $321.00
Setting: B4 Touring Class (TC)
Drive Type: 4WD
Position: Front
Old Part Number: F4-B46-1727-H0 (that's a zero)

Rear:
46mm Monotube Shock Absorber

New Part Number: (24-017275)
MSRP: $321.00
Setting: B4 Touring Class (TC)
Drive Type: 4WD
Position: Front
Old Part Number: F4-B46-1727-H0 (another zero)

The HD shocks B6 do not fit - according the voice of Bilstein they fit the 400GE model that I am not familiar with.

Of course, you should check with Bilstein before you order.

We'll see how quickly and what type of accommodations the manufacturer on down the chain will make since there is a rather big delta in price.

Not to mention spending valuable time....

Same P/N for front at rear? Methinks not.

Are you referring to Bilstein or MB dealers?

Bilstein dealers; MB has them listed as "shock"

Dutch, thanks for pointing that out. I just got an iPAD and I am not adroit with it yet. Here is the correct number -

46mm Monotube Shock Absorber

Part Number: 24-017282
MSRP: $329.00
Old Part Number: F4-B46-1728-H0

Setting: B4 Touring Class (TC)
Bilstein B4 Touring Class gas pressure shocks and struts are designed to be the economical choice for maintaining the original equipment ride performance while incorporating Bilstein's world-famous durability and precise construction. (black paint, steel body)

Drive Type: 4WD
Position: Rear
Quantity Per Vehicle: 2

We finally received the correct TC series Bilsteins and installed them along with my usual 40k mile transmission fluid change. In preparation I washed the undercarriage and put penetrating oil on the shock nuts.

The new Bilsteins fit perfectly, and are, significantly, the same and only size recommended for the G55. (NB, the bilstein us web site still has the errant HD part numbers listed for the G500 only. These fit the Ge400 Model only. Beware! The G 55 fitments are correct for both civilian trucks.)

NB: one has to be very careful removing the US drivers side front damper as the top chassis mounting points run near the traction control system. Two people make the job easier by far.

The new Bilsteins have a sticker that identifies them. The stock shocks have no sticker and are listed by MB as "shock" so the brand is unclear. According to a BA factory spokesman, the TCs for the G series are high pressure mono tube shocks like the HDs and with similar damping characteristics. I am going to send the old shocks back to Bilstein as the factory will rebuild them for $65 each with a full lifetime warranty, according to a BA spokesperson. If the are not theirs they can chuck them.

During installation we cleaned and touched up a few rust spots with Rustoleum, a sensible touch. We also used antiseize on the hubs as we had to reinstall the wheels.

Driving the car now is a revelation. There is much less body lean in turns, the ride is smooth yet firm, and driving the car is less fatiguing.

Continuing I had a chance to drive a G55 at the Monticello event. I really enjoyed that beast. It has a wonderful engine and exhaust note but is much lower spring and tire wise than my G500. One has to step or pull oneself up into the 500whereas one can comfortably step into the AMG. (I stand over 6'tall.) the 55 was a gas to drive and had instant power.

With the fresh Bilsteins The 500 now handles much more like the AMG but is softer and has less raw power. It is fine for me as I use it off road where power is les important than sufficient torque, suspension travel, and ground clearance. I would be happy with either vehicle but as they say "horses for courses". If you have a G500with over 50k miles I would seriously consider the TC Bilsteins. They are worth every $. Shox.com was my supplier.

A disconcerting fact is that the front electronics on the transmission body haveNO shield. For any vehicle, let alone, an off road vehicle this is unacceptable since moisture as well as rocks can damage the unit leaving one stranded. MB should develop a retrofit shield immediately!

You must be Daddy longlegs! I'm 6' and still have to prop myself up to get in my G55.

I was overstating a point to make one! I think the G55 is super!