Hi all, does anyone have an Obunsha Teikin pocket pen? The one with the Parker 180 style nib? How are they as writers and are there structural problems I have to be aware of like an easily cracked section, etc.? I'd also like to ask if anyone knows the going rate for these, if user grade. I checked eBay and only found one listing (for bidding). Attached is a photo of the pen from the seller. The Teikin is the one second from the bottom, alongside a Platinum DP-50, a no name pen, a Pilot DPP-100, and a Platinum DP-800 (or an older version of it). Thanks!