It's not an 1810 impression though. The Marines-batallions were formed in 1806 'To last until the end of the campaign' and were the third batallions of the 2nd, 3rd, 7th and 8th Regiment. They were probably sent home in 1807 or 1808 because the 7th and 8th regiment, are given as only consisting of two batallions in early 1809.
That's not to say that the marines didn't exist anymore in 1810, but why call them 1810? Why not call them 1806-10, or 1807? To me, it feels like this entire '1810' impression was made solely to legitimize the incoorperation of the Marines into the Re-enactment Bylandt Brigade - which, either way, doesn't make a lot of sense from a historic perspective and seems entirely driven by re-enactment politics and the wishes of a few people. Historical arguments take the backseat, only used when it favours those wishes and ignored when it doesn't.
I should probably give myself a punishment for off-topic posting by now. Hell, if you showed this to any Dutch re-enactor that knows me he would probably respond 'oh well, Casper be bitching again', which is undoubtly true, but I'm not just bitching for the bitching. There's just a lot of bullshit in re-enactment that everybody seems to know of yet refuses to publically acknowledge. Anyway, time to make a new thread for generic Re-enactment discussion.