Welcome! Awaiting your finding with anticipation. Of course, ancients used alters. Curious as to why such a symbol would have been lost for a period of time.
Well, brother, a lot of the early documents discussing masonry (starting with maybe the Regius poem, for example) make no mention of an altar. It doesn't appear to have always been a fixture of the Craft.
Fast forward to the 1700's and
Three Distinct Knocks and
Jachin and Boaz. Exposures aren't Gospel truth, but some things can be taken away from them. Namely: no altar is used in the ceremonies of either of these degrees. In the 1730 exposure, the Master holds the VSL, while in the 1760 exposure, it rests on a simple stool.
I'd go into more detail, but that would spoil the fun of reading the next issue of TLR's Transactions.
It's my humble opinion that most, if not all, Freemasons in Texas should be members of the Texas Lodge of Research. Associate Members, at least. It's interesting to meet so many men who have researched one facet or another of our noble fraternity and read their work in the Transactions and elsewhere.