Big Jake :

I had to check on your question about when would you see eggs in BG 2 mths from spawning.

I found no direct answer to the question but here is some info which will help. This source cited an article on BG oocyte and gonadal development which I don't have acces to.This study used GSF but stated the results were similar to what was observed in BG.

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In contrast to the males, experimental
studies have shown that spring-spawning fe -
males have shown a more consistent pattern of
requirements for both long photoperiods and
elevated water temperatures for stimulating
advanced stages of oocyte maturation.
Sexual differences within species have also
been described with different photoperiod or
temperature requirements for spermatogenesis
and for maturation of oocytes.

In a descriptive study of a closely
related species Lepomis macrochirs, James
(1946) describead period of gonadal quiescence du
ring the winter followed by a period
of active gametogenesis in the spring, concomitant with the seasonal increases in day length and temperature. This latter suggestive
relationship was the subject of this investigation, with Lepomis cyanellus...

This is in
agreement with the relationship observed in
nature where rapid gametogenesis occurs only
after water temperatures have greatly increased
(to about 18-20 C) from winter levels
and under photoperiods which have increased
to about 14 hr and are continuing to increase.

Specimens captured in midwinter
and subjected to a long photoperiod high
temperature (20 C) combination initiated
gonadal recrudescence and within 28 days attained the gonosomatic values,
oocyte diameters, and testicular histology
of functionally mature fish.

Again, the long photoperiod-
high temperature combination produced
mature gonads in both sexes by the first sampling date, 21 days in this experiment.

Based on this I would make a "wild guess" and say you should see ripe eggs by at least, around 21 days after the female fish are holding in water 60-68 degrees and with a photo period of 14 hrs. For what it is worth. The fish that were holding deep will probably move shallow soon and 21-28 days later will be ripe with fully developed eggs and be ready to spawn.