The mounting type you describe is "Braze on" as opposed to "Band on"
Pretty certain the current 105 R7000 item won't fit as I think the chainring spacing is different. It's also worth mentioning that the preceding 105 (5801) also runs a different cable retention / arm geometry, so you'd probably be advised to avoid this too in case it creates and cable routing / length issues. I think your most likey issue would be cable pull ratio, but I'm not sure if these have changed appreciable for Shimano's gearing (they did a while ago for their braking setup).
Tbh I'd expect you to OK with a current Tiagra, Sora or even Claris replacement, but I'll leave this to the more knowledgeable to confirm
EDIT: Missed the bit about being a triple; so the last two iterations of 105 are out anyway. Tiagra and below if you want a triple!