Then how were those local-to-Santa-Fe ads inserted into the broadcast? I listened to their old stream several times and noted commercials for Santa Fe carpet stores, car dealers and event promos that were not heard on 103.7 - similar to when a TV semi-satellite inserts local advertising for a particular side of the market (do KOB-TV and KRQE still do that for KOBR and KBIM?)
I've never worked there. So, I can't tell you. I can, however, offer a few theories:
If you heard it online, you might have heard specific online ads. As you probably already know, commercials you hear online are rarely a reflection of what goes out over the air.
Also possible is, at some point, the translator could've started relaying KSFE 96.7 out of Grants rather than 103.7, which it originally stated it was using. KSFE aired the Oasis format at one point, too. FCC requirements for translators to notify it of a change in originating stations are notoriously lax. If you check current FCC records, 95.9 relays KSFE. We won't be able to ascertain exactly when that started happening. The FCC database mentions 95.9 relaying 96.7 in mid-2013. It could've started doing so long before that and remained totally legal. Vanguard might have tried selling specific ads for Santa Fe and needed a different full-power originating station to accomplish that. 96.7 would've been the perfect source as nothing in Grants does much revenue. A translator in Santa Fe should easily outbill a full-power Grants station. (See 95.3 in Grants for more information on that.)
As non-fill-in translators can't accept payment for relaying other stations, I believe they can still air a handful of ads they sell themselves. I was thinking it was 30 seconds an hour, but I'm not 100% certain what those requirements are. So, you might have heard an ad or two like that. Fortunately, I've never owned or worked for a translator. So, I don't know much about the ins and outs of that part of the business.