I misunderstood your 10-year comment toward the end; only now understanding that you and your partner have been together only a year. That increases my confidence that current infidelity isn't an issue. But assuming that either or both of you were sexually active with other partners until fairly soon before your relationship began, the situation is entirely compatible with either of you bring recently infected with HSV-2, molluscum, or both. I don't see any mystery here at all.
First and most important, a positive culture for HSV is the most definitive form of diagnosis of genital herpes; it always outweighs blood test results. The only slight wrinkle is that 24 hours is fast for a culture, especially one that already knows virus type. However, it is possible that the lab actually does a PCR test rather than culture, in which case such rapid results are the norm. So your wife has HSV-2. (Of course it's always a good idea to ask the provider for reassurance there isn't an error like specimen mix-up with another patient.)
I don't understand your comment about HSV versus MCV culture. There is no culture test for molluscum. In any case, while it is true her HSV-2 ELISA result is on the low side, it is in the positive range and entirely consisteng with her being infected with HSV-2.
Your story is quite typical. Genital herpes due to HSV-2 often appears in truly monogamous couples, either because the infected person has had it all along, but previously had no symptoms; or because his or her partner had it all along, and transmission only occurred recently.
As to finding "the answers we need", you're already planning to have an HSV-2 ELISA yourself. Most likely you will find it is positive. Whether positive or negative, there is no need to invoke infidelity to explain the situation. Either or both of you could have brought the infection into the relationship from other partners more than 10 years ago. As I said, this situation is quite common.
And for what it is worth, molluscum in the genital area is often but not exclusively sexually transmitted. One of you could have caught it from, say, an infected child in your environment (MC is primarily an infection of toddlers), then transmitted it sexually to the other.
Having said all that, my responses take you at your word about no chance for either of you to have had other sex partners. Without that reassurance, I would have raised the possiblity; it is a bit of a coincidence for both these infections to pop up within a few months of each other. But you can judge your relationship; I cannot.
I hope this helps. Best wishes-- HHH, MD