Mamiya RZ Lenses with "Mamiya-Sekor" ground off?

[hamradio]

I thought this was exclusive to a lens I used to own, a 90mm f/3.5 for the RZ67. "Mamiya-Sekor" was ground away and filled in with black paint, as was "Seiko." The serial number remained, however.

I was surfing ebay this morning, and found another. I thought that it was my old lens, but it is not.

http://www.ebay.com/itm/Vintage-MAMIYA-SEKOR-f-90mm-1-3-5-Lens-for-a-RZ67-Camera/221549513611?

I've attached a couple photos from my old lens. I'm baffled why someone would grind away the name of a shutter manufacturer...when I worked as an auto mechanic, we regularly dealt with new OEM parts from third-party vendors with the original manufacturer logos ground off, as they were being sold below dealer list price under a different brand. However, I don't think that is the case here...

 

[sevo]

It was more common before the eighties, but even in the RZ era there may have been countries left where the local representative had exclusive rights to the brand - in these places, imports by another party were required to be de-branded to pass the customs. Or it may have been marketed to an embargoed country. Or embedded into some other product (say, a medical camera) at enough of a markup that the maker of that devices wanted to obscure the origin of his components.

 

[hamradio]

Aha, that makes sense! Thanks!