I was trying to replace the struts on my 82' 300TD (American not European) wagon's rear door and I came across a bolt that required a 7mm Spline bit - one of those things that looks like a torx bit but instead of 6 points, they have 12.

I bought a set of bits online but it only came with even sizes - it had 6mm and 8mm. I even asked the mechanics at the MB dealership if they knew how to find a 7mm but the guy who had been working on interiors there for 20 years said he had never seen one and all he could find in the shop was 6mm and 8mm. He had never even seen a bit like that used for the struts - only torx.

When I searched online, even European tool suppliers don't seem to stock the 7mm - they have 5mm, 6mm, 8mm, 9mm, etc. But no 7mm.

I have just about resigned myself to using a dremel to cut a grove in the bolt for a flat head screwdriver but that can be a pain and it is a big bolt. I figured I would give this forum a try. Does anyone have one of these things?
How the heck did you get it? Are you open to putting it in the tool-loaning program?

Thanks,
Sasha