Following advice from Fabrice and Callum, I and Dan rotated them 90 degrees and put them in a (hopefully) correct direction.

We didn't use thick washers between the absorber flame and the base plate, partly because it would have been a pain to do so, partly because the screws available were somewhat short (it didn't go all the way through the base plate) and using washers would have reduced the number of screw threads that were engaged.