My 170Vb has the same material, a heavy cotton weave ribbon. Niemoeller has this, it is part number A 50 020A (MB# 000 098 10 35). They also list the same rubber profile that is used on the cowl, Niemoeller A 50 020 (MB# 000 987 09 35).
By the way, where are you getting your grill chromed? I need to eventually do the same, and we are in the same area of southern California.