Sorry to take so long to respond. Just saw your message today.
Yes, I really liked that front storage box. Believe me, we searched a long time to find one that would fit. Most were too wide. My recollection is I bought it at either Home Depot or Lowe's. Since they're across the street from each other here, I'm not sure which one.
In any event, as we began the build process on our 19', I searched both locations again and could not find it. Neither Home Depot or Lowe's staff knew what I was talking about. Not much help. Now all they seem to carry are metal boxes.
The charcoal-colored box was the only one we could find where the lid actually opened without harming the fiberglass shell. The box even stopped the propane cover from wiggling with its snug fit.
We remain in touch with the folks who bought our 17. If you want to pursue this, I could write them and ask if there is a brand name on the box [don't recall that there was one], along with the dimensions. Let me know if you want me to check with them.
When we ordered our 19, we were pleasantly surprised that ETI provided the fiberglass front storage box at no charge for returning customers. After that, we didn't need to search for another one.