I'm pleased enough to have finally cracked this process myself(you don't even want to think about how many poor wee dreads have died previously to my barber-secretly-chopping-up-people-for-pies level plasticard surgery "skills"

) that I'm posting a
WiP, which I rarely do. I made sure to put "truescale" in quote marks because I know how het-up some folk get over the matter if you don't constantly acknowledge that there's an element of personal preference at play.
The "truescale" I've chosen to work with is ~40mm = ~2.3m(on the reasoning that just under 7.5 feet is a happy medium for all the various depictions of
SM over the years in model, art, and writing, and that a fully upright Primaris is about 40mm tall, ending up roughly the right height relative to the 32mm-ish tall modern
GW plastic humans - using Primaris as the basis for "truescaling" is the best combo of effort vs result I've yet tried, and since I'm ignoring the new fluff I won't have to worry about making "truescale" Primaris, hah). The issue though has always been vehicles - the moment you upscale your
SM infantry, the vehicles look a touch comical by comparison. Many unfortunate experiments later I've almost got down a process to make Castraferrum Dreadnoughts the "proper" height at around ~64mm(though I'll be changing the process on the legs to make misalignment less of an issue on the next one and will probably use these legs for an Ironclad where I can cover the dodgy bits with armour plating - this guy sits a couple of
mm short because the misalignments affected the stance a bit) while maintaining roughly the right proportions:
The arms and greave plates are placeholders while I wait for a Venerable kit to arrive and obviously there's a lot of remedial putty work to do before I can even start properly detailing, but the basic form is complete - the torso was increased in height and width by 2mm, as were the arms; a 1mm spacer is placed below dome atop the hips; the hip assembly itself has been widened by 4mm, and the legs have had 3mm of extra height added(2mm above the knee, 1mm below), while the feet have had 2mm added to the height and each toe has been widened by 1mm and deepened by 2.5mm. For a "normal" dread I'd use two sarcophagus plates with the detailing removed, lengthen both by 2mm at the bottom, then trim away the left of one and the right of the other to form a single larger plate.