Hey if you squint hard, squeeze some lemon juice in your eyes and just generally don't pay any attention it looks like it's got a 10.X" barrel instead of a 14.5.
Sure can if you have the right tools to get off the DD forend and barrel nut then attach the Specna, they should be the same thread. It'd be a better idea to go with an M-LOK rail because that attachment system largely replaced KeyMod as the defacto gold standard about a decade ago now; much more accessories available and KeyMod accessory production will only ever decrease over time (will fizzle out entirely in not too long I'd wager). But then it depends what you want to attach.
So hard to tell from the pics of the Speca.. looks close to the right length and it'd be really weird for them to make specifically wrong and oddball 13.5" barrel when they'll already have a machine spitting out 14.5s for other guns constantly, but it doesn't look quite right either.. weird.