I'm afraid the Barons don't fit. A Baronet is one rank lower, a sort of hereditary knighthood and, unlike a Baron, was not a member of the House of Lords.
And, if I can trust my edition of Fairbairn's Crests, the Bowyer crest (a falcon rising, belled) does not match.
Although the British Order of St John received its charter in 1888, its origins go back to the early 1830s so not necessarily incompatible with a hallmark for 1835. The Order of Malta is Roman Catholic; the British Order of St John is Church of England in origin. Assuming we are right about the significance of the cross, which order it represents would reflect the religion of the bearer.
Sorry tio mud the waters. I fear it would be a massive task to plough through a list of Baronets and check the family crests for each one or to work backwards from illustrations of crests to find a matching baronet. This cannot be the only example of this combined crest so I wonder whether we might hope that somebody has already done the work!