The 1874 RLDS edition replaced the past-tense made with the infinitive verb form make. The 1908 RLDS edition restored the original made. Either reading is theoretically possible here, so we follow the earliest reading (“and made swords out of steel”).
One wonders here if the direct object for the verb molten might be missing. Elsewhere in the text, this verb always takes an explicit direct object:
One possibility here in Ether 7:9 is that the original text read “and he did molten ore out of the hill”. The visual similarity between ore and out may have led to the accidental omission of ore when Oliver Cowdery copied the text from 𝓞 into 𝓟. The visual similarity between the two words is increased if ore was spelled as oar in 𝓞 in this sentence. Elsewhere in the manuscripts, we get the following statistics for Oliver’s spellings of ore (I also list here the statistics for the plural ores, which Oliver never misspelled as oars in the Book of Mormon manuscripts):
𝓞 𝓟
ore 4 6
ores 1 2
oar 1 5
oars 0 0
In fact, since Oliver Cowdery’s a’s often looked like u’s (see under Mormon 6:2), an instance of oar in 𝓞 might look more like our, thus almost identical to out, thereby allowing for the accidental loss of oar (that is, ore) before out.
Of course, another possibility here in Ether 7:8 is that the direct object has been left unstated since one knows it would have been ore or metal that would have been molten. There are, for instance, a number of other verbs in the Book of Mormon where the direct object is left unspecified, as in the following examples that are discussed under each of their respective passages:
To be sure, “he did molten out of the hill” sounds strange, but that may simply be because we are not familiar with the verb molten (see the discussion under Ether 3:1). Yet since it is possible for the direct object to be lacking for the verb molten, the critical text will retain the earliest text here in Ether 7:8 without any explicit direct object for this verb.
Summary: Retain the lack of a direct object for the transitive verb molten in Ether 7:8; the direct object can be left unstated here since the reader would automatically know that it would have been ore or metal.