Nokia is expected to continue focusing on Windows Phone-based hardware despite dipping its toes in Android’s openness recently, and the next WP handheld is likely called Lumia 630.

lumia 630 Presumed Nokia Lumia 630 handheld visits the FCC, may debut April 19

Did anyone ask for a budget-conscious Nokia Lumia with slightly superior specs compared to the 520 and 525? Then it’s time to rejoice, as the Lumia 630, codenamed Moneypenny, has just moved one step closer to a formal announcement.

Said intro may happen on April 19, according to usually reliable industry leaker @evleaks, in which case scoring FCC’s regulatory approvals this week makes perfect sense. After all, you don’t want to wait until the eleventh hour to get the Commission’s blessing.

Disguised under an RM-976 model number mentioned in multiple previous reports, the single-SIM Lumia 630 visited the FCC alone. As in not chaperoned by the dual-SIM Lumia 635, aka RM-977 or RM-978, the purported first ever Windows Phone capable of accommodating two SIM cards at once.

But fret not, they’re both looming large on the horizon. Some speculated the 630/635 duo might even break cover as early as April 2, when Microsoft’s Build Developer Conference kicks off in San Francisco.

Nokia Lumia 630 FCC Presumed Nokia Lumia 630 handheld visits the FCC, may debut April 19

Either way, RM-976’s FCC approval docs set the phone’s dimensions in stone – 129.5 mm height and 66.7 mm width – as well as its microSD support, Wi-Fi, Bluetooth, GPS and 3G connectivity options. Taking into account the unavoidable bezels, Lumia 630’s usable screen real estate shall come in at roughly 4.5 inches. Probably, with 720p resolution.

The on-board software version is a question mark, as Microsoft is almost ready to launch Windows Phone 8.1, but worst case scenario, the 4.5 incher(s) will run WP8 out the box and grab an OTA upgrade soon after their rollout.

Now, if we could only get the pricing scoop to find out exactly where the pair places on Nokia’s totem pole. Above the Lumia 520 and 525, but what kind of a gap are we looking at exactly?

Sources: Phone Arena, FCC, Twitter