We've been allocated seats 34 and 37 on EuroCity-Express (ECE) 451. I tried to find a seating plan for this train but couldn't find one. This forum post appears confusingly unrelated despite talking about ECE maps. The ticket says they're both aisle seats. Are those two seats opposite each other, adjacent with a corridor in-between, behind each other, or none of those?
The Man in Seat 61 has a page with Europe train seat plans. Although he links to this Dropbox page for the Switzerland-Milan EuroCity, it doesn't seem to cover the EuroCity-Express. I can't find it at vagonweb either.