W123 300D CV axles - Altrom / Napa

[Graham]

My local shop quoted me on installing new axles from Altrom.

I looked these up and found just one vendor who offered them. I think NAPA also offers them. I would likely have shop supply axles, but just researching what it is they offered.

As you can see from link below, the vendor offers two Altrom axles. One has Altrom number 651401, the other 1073504310 (which is an MB number, but still Altrom part, it seems). The prices are hugely different! Can anyone see what the difference might be?

MERCEDES-BENZ 1985 300D TURBO DIESEL Constant Velocity (CV) Driveshaft | ALT-651401 ALT-1073504310 | Best Auto Parts Canada - Cheap Auto Parts Online

I will try calling them in morning. The 651401 price is fine (about US$109, no core charge) but not the other one! NAPA also shows a crazy price for 1073504310. I did check PP and they have good pricing on axles, but once shipping to Canada is added the cost more than doubles!