Do not put too much money in this boat. It is not in high demand. You will not get your money back when you sell.
but then, neither is yours. very few boats are.... boats in general, yes, but very few particular brands or models can be considered in "high demand", and ANY boat with parts missing is in even less demand, but by fixing it, it can bring the value up, or at the very least make it usable.
And its a less than one percent of the average boat owner that will ever get the money we spent on our boats back, if we were to sell it.
most of those that claim they do, has a poor memory and hasnt kept very good track of their receipts.
as for the OP's mac25, anyone who has sailed a 25
and a 26, which is the newer model and considered to be in higher demand, knows the 25 is a more comfortable boat and arguably a better sailing boat... so I dont think he is wrong in his desires, but I do agree he may find a used keel for it cheaper than making one..... I have found patience is truly a virtue when searching for boat parts....