Two types of furniture (heavy and light)

[lestodante]

the holes in the back of the models are usually caused by a not perfect cast (air bubbles).
The metal mold they used has a high cost but it depends on how many copies you need to print... on a high number, like Heroquest was, they will probably find more economic to create a new mould.
Another option, is they tried to prevent damages to the pieces, the skeletios weapons are more protected in the new mold.
Figures have slighty variants with feet "drowing" into the base more or less than others, it means they already did alternate molds in the past rebasing the figures in a different position.

[HispaZargon]

the holes in the back of the models are usually caused by a not perfect cast (air bubbles).
The metal mold they used has a high cost but it depends on how many copies you need to print... on a high number, like Heroquest was, they will probably find more economic to create a new mould.
Another option, is they tried to prevent damages to the pieces, the skeletios weapons are more protected in the new mold.
Figures have slighty variants with feet "drowing" into the base more or less than others, it means they already did alternate molds in the past rebasing the figures in a different position.

Yeah, I think so.

The costs of manufacturing new moulds were not have been a problem a that time since HeroQuest was a product sold in many markets, and very well sold... as we know, it was an incredible commercial success, so, I think the design changes would be mainly motivated by other reasons.

Reducing the risk of damage at miniatures could be also another improvement, moreover, Advanced Quest box was much taller than the european original game box, probably in order to avoid accidental breaks of the Barbarian sword or Fimirs axe if they were stored in "stand up" position. I remember to have read somewhere that HeroQuest customers wrote to MB claming about such problem and they considered it in the new box design but, maybe I am wrong.

And yes, I also noticed the feet differences detail. As a consequence of that, for example the Chaos Warlock miniature is a little bit more backwards inclinated as mentioned before. The same occur with other miniatures. I also remember that my first ROWL EU expansion originally had all the top zone of the miniatures bases 1 or 2 millimeters taller than the same miniatures of my original basic game. I always thought it was some kind of production non conformance but, according to your words, it would be posible that they use another not-exactly-the-same mould in that case.

[iKarith]

I know that the first English edition at least had a problem that the chipboard components were often (always?) misaligned from the die cuts. Badly misaligned, actually, and in a predictable way, particularly notable on doors but appearing elsewhere as well. This was fixed in the NA version at least, though I've seen variances in color and alignment in those as well suggesting some slop in the tooling from batch to batch or from wear with time, and perhaps different pigments used in the printing over time.

My French bits set came with a full complement of doors, most of with cellophane tape wrapped around the base so that the door couldn't slip out. It would if you just tipped it upside-down otherwise. The others I have are a hair's breadth thicker, I forget what I measured the difference to be, but it was well under a millimeter and the same base holds them fairly well. I've wondered what I might do for the thinner doors to fix that.

[HispaZargon]

I know that the first English edition at least had a problem that the chipboard components were often (always?) misaligned from the die cuts. Badly misaligned, actually, and in a predictable way, particularly notable on doors but appearing elsewhere as well. This was fixed in the NA version at least, though I've seen variances in color and alignment in those as well suggesting some slop in the tooling from batch to batch or from wear with time, and perhaps different pigments used in the printing over time.

Well... it appears to be a manufacturing deviation. It would be normal, at some point, in the first product deliveries, which mouldings were probably later corrected as already mentioned.

[cynthialee]

I know that the first English edition at least had a problem that the chipboard components were often (always?) misaligned from the die cuts. Badly misaligned, actually, and in a predictable way, particularly notable on doors but appearing elsewhere as well. This was fixed in the NA version at least, though I've seen variances in color and alignment in those as well suggesting some slop in the tooling from batch to batch or from wear with time, and perhaps different pigments used in the printing over time.

My French bits set came with a full complement of doors, most of with cellophane tape wrapped around the base so that the door couldn't slip out. It would if you just tipped it upside-down otherwise. The others I have are a hair's breadth thicker, I forget what I measured the difference to be, but it was well under a millimeter and the same base holds them fairly well. I've wondered what I might do for the thinner doors to fix that.

Make a tiny paper shim for the thing. Should tighten it up nicely once you find the right size and fold.