In June 2016 Konstantin sent me a link to a Japanese website: http://soltec.exblog.jp/24074967/ . I found that Google Translate provide sufficient English text to allow me to work out what he was up to.
The article (part 3 of a series) describes how the author fitted a SATA socket to the circuit board adjacent to the
IDE connector and some other small mechanical mods so that a SSD could be plugged in to it.
He also tried fitting three drives (2 x SATA and IDE) to see if there was any priority in
the order that the BIOS would boot operating systems.
Part 1 deals with adding a wireless lan card using the Mini PCI Express connector.
Part 2 deals with fitting a SATA to mSATA convertor board.
Part 3 is actually about the t510.
In January 2019 'tos' got in touch.
He had made a 'fat' t5740 by using the case from a dead
t5740 to house two 3.5" drives which was then mated with a functional t5740 that had been
modified to provide the necessary 12V on the SATA interface.
The article is in Polish,
but Google translate does a good job of rendering it in English.
In October 2019 I heard from Matthew. He had used a t5740 as the basis of a NVR (Network Video
Recorder) for a security camera. The software aspect was handled by ZoneMinder
running on Xubuntu. You can read about it in his
blog