Micro Seiki MA-505 variants - any oracles around?

This thread has only been dormant for a couple of months, so why not bring it back?

I recently acquired an MA-505L, and mounted it on a Technics SP-25 with the standard SH-15B1 plinth.  With a 270mm spindle-to-pivot distance, the arm *barely* fits under the dustcover...naturally only when the arm is  docked.  Sound is quite good.  I think there is something to this 'reduced tracking error' thing with longer arms ;)

I'd love to find more information about the various headshells for the 505 arms.  I'm aware of the H-303, H-202, and even the H-40.  These all have a similar design/shape, with perhaps only the holes drilled for weight/balance being the difference?  Surely they are all made from milled aluminum, and only the number of holes drilled is the difference for weight.  I see a bit of variance in listings on eBay.  

The headshell weight is particularly critical with the longer 505L when trying to obtain zero balance.  In order to get my current setup balanced, I had to use the extra counterweight on the back of the arm, but also tack a US dime to the headshell on the front - not ideal, but it works!

Uberwaltz, Hi- I built your table! Was looking up the 505X which I was not familiar with and there you were.
Hope the 401 + 505 combo is still making you smile.
I love the 505 because it is such a flexible arm and looks great to boot.
Best, Dave

i myself would hope to hear from Uber......

How can you visually determine what version you have?

totem, "arm found on Micro Seiki DD-40 turntable, still identified
as an MA-505 although different from the arms sold
on their own".

Other than the base for each arm, what is the difference?  From a quick look they appear to be identical.