I'd put both of the mystery anodes to Gnd if you are
not aware of any signal use.
Peculiar that the pullup resistor and filter cap have "DNF"
values. I'm aware of "DNI" (Do Not Install).
You want a Schottky with a low enough Vf that you make
an in-spec VIL at the receiving IC (according to its ratings)
from a barely-in-spec reset level (which may be TTL if a
legacy system).
Could be a bind, with TTL VOL at 400mV and VIL often being
20% of VDD (so 0.66V at nominal, 0.7 at high 3.3V) and
the Schottky Vf occupying the vanishing middle ground.
More likely this scheme was for old TTL where VIL(max)
was 0.8-ish and threshold, about 1.4V with no Idd penalty
for kissing the limit (unlike CMOS, where there will be
shoot-through current in the input buffers all across the
VILmax-VIHmin range).