A $60k loss for the difference between the FMV $90 and the $30k Paid by His Son
no since no loss is reportable for a gift
in your situation even if this was a straight-out sale $30K received for $90K FMV IRC 267(c)(4) would bar a loss because it's between related taxpayers.
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A $30k gift for the difference between A's $60k Adjusted Basis and the $30k Paid by His Son
no since a gift tax return is required when the value of gifts to any one donee in a year exceeds $17,000 2023.
the gift here is its FMV over any consideration received. so here it would be $60 and reported on form 709 not 1040.
your scenario is different since FMV $175 Tax Basis $151 before the gift and proceeds received $125 with a gift of equity of $50. so does A report $175 less $151 or $151 less $151 or $125 less $151 with the loss not allowed because of IRC 267(c)(4) or $125 less ($151 reduced by a prorata portion that equates to the gift (50/175*151). or something else completely.
I agree with your latter thread you really need to sit down with a tax pro and go over everything including what you are trying to accomplish. It may be that you can accomplish goal A or B but not both.
