[GreenKeys] Fuse holder?

[John, W9DDD]

I was looking to replace a missing fuse holder cap.

I identified the fuse holder as being a Bussmann HKP series.

Did Teletype have the gray fuse holders made as special order for them, 
or was there a choice back in the day?

So far I've not seen a color choice.  Was gray a different rating of 
some kind?  Or maybe Bussmann had similar part that they've discontinued 
that wasn't HKP?

I can live with a black cap on a gray housing, it's just that I got 
curious about the difference.

-- 
John, W9DDD
Ich habe dreimal abgeschnitten uns jetzt zu kurtz. (I cut it off 3 times 
and it's still too short.)