For my part, it didn't get much farther than a few scrawled notes and a couple brief paragraphs before the project was sidelined in favor of...I forget what came out instead. I did find the file that has my brief paragraphs, and here it is. I present, for your perusal, all of Monstrous Mechs that was completed (to my knowledge anyway):
The Sea Throne
A slathem who calls himself Lord Druun has found a powerful magical artifact at the bottom of the sea. The Sea Throne allows its owner to create around himself a huge humanoid vehicle composed entirely of water. The Sea Throne is an intelligent artifact with an agenda against land dwellers, and it has convinced Lord Druun that the land races are responsible for the lunar invasion which has so troubled his people. Lord Druun sits the Sea Throne at the center of his watery mech and wages his war against the land. Even the most hardened mech pilot feels some apprehension at the idea of being drowned in his own mech.
The description will include not only the Sea Throne water mech, but also the Sea Throne artifact and some water-based spells that Lord Druun uses against land mechs.
The Walking Monastery
Boromandithides is an old god, with little power left to fight against the lunar gods. His few remaining followers have largely been destroyed by lunar rains and lunar creatures. When he heard the monks of his last monastery fervently praying for salvation from the orc mechs approaching, he intervened in the only way he had power left to do. The stone monastery rose from the ground, took humanoid form, and crushed the orcs. The monastery mech now wanders the land guided directly by Boromandithides’ hand…or so the monks think. In reality, Boromandithides himself has inhabited the monastery in a last-ditch effort to avoid his destruction at the hands of the lunar gods, and to protect his last followers while doing so.
Additionally, a mobile village has begun following Boromandithides around. It started as slaves freed from the orcs, but has grown as the god travels the land. The mech travels Highpoint under its own power. The monks of the monastery and the villagers often do not agree on why the god goes where he does, and the god does not have the power yet to communicate directly with his followers.
The physical monastic form of Boromandithides is composed entirely of stone blocks that shift under the god’s will. It is very slow, and has no armaments other than rocky fists. It protects itself and its followers through the powers of an admittedly weak deity. Numerous adventures can be had following the monastery around and trying to divine its purpose at each stop. There are also political hooks using the tension between the monks and the villagers.
If the book were to go forward now, are these the things I'd submit? Probably not. Although if I recall Lord Druun did get mention or two in Almanac of the Endless Traders.