I have a few Philips HRL10 fixtures: 3 equipped with HPL-N 80W and one that has been converted to a SOX18W version. Three have the oval glass bowl and one has a bathtub shaped plastic bowl.

Glass bowl examples from fellow LG members:

http://www.lighting-gallery.net/gallery/displayimage.php?album=42&pos=41&pid=14996
http://www.lighting-gallery.net/gallery/displayimage.php?album=1380&pos=28&pid=44809

I have a few general questions about the HRL10 fixture:

Is the HRL10 made in Holland or in England? Did Philips make it themselves or did they buy the HRL10 from Eleco which has a nearly identical fixture called HW918?

The SOX conversion set that I have has lost its paper typeplate. What does it say on the typeplate: HRL10 of possibly XRL10 (X standing for SOX in Philips nomenclatura)? Where is this set manufactured? Possibly in Oss (LA code)? Who can look up this missing label for me?

I seem to remember that some HRL10 were converted to 2x SOX18W as a replacement for the HPL_N 125W. Would that be correct? It seems possible since the plastic bowl offers room for two SOX18W lamps...

I only can answer one of your questions:

Philips sold an seperate unit to modify the MV to LPS. This unit had a code: HRLUN
So far as I can tell it was only available with 1 LPS not 2.

Thanks for answering though. I have been able to restore a Philips HRL10 with a 1x SOX18W. Nice fixture!

I think the Philips HRL10 was a British product. In the early 1970s Philips' product range in Britain consisted of both British and Dutch products, and the British made products were all identical to products offered by other manufacturers such as Eleco and Phosco. I think Philips were licensed to rebrand other manufacturers' lanterns, and that helped them to enter the lantern market. Perhaps Philips selling the HRL10 in the Netherlands was some form of tool for ensuring a good business relationship with Eleco. Certainly, I am aware of the Eleco HW918 being produced before and after the Philips HRL10, from about 1960 to the late 1980s.

My impression too is that the HRL10 is actually a British made  product: the bolts used to fasten the socket and its bracket have non-metric thread. I guess that Eloco from the UK made the HRL10 with the cast Philips logo exclusively for Philips.

A few Eleco products were also sold as Philips products overseas. Given the design of the lanterns, including things like the bowl clips, along with the fact that extended options or similar design lanterns were available from Eleco, I would say they were Eleco products made under license. They share characteristics of other Eleco products of the period, not other Philips products. And yes, Philips did sell some Eleco (and also Phosco) products in the UK in the early 1970s before the legendary MA90/50/60 (SRS201) appeared.