Don't worry too much about the retaining hole locations. I carry a 44 lb Bruce and a 35 lb Delta on the bow of my 34'. The retaining holes were not correctly located for either anchor. A couple of hours work fixed both.
I went to the junk yard and found a piece of 1/8" thick by 1-1/2" wide stainless steel flat that I suspect is 304. From McMaster-Carr, I bought a piece of 7/16" stainless round, some large split rings, and some safety pins. At Lowes I bought four short 1/2" bolts and nuts.
At the boat I measured the distances from the bolt that serves as the axel of the roller to the existing retaining pin hole and the distance from that hole to the hole in the anchor. In the case of both the port and starboard anchors the three holes were arranged in a straight line.
At home I marked the three 1/2" hole locations on the stainless flat and struck 1-1/2" diameter arcs around the first and third holes. Then I drilled the holes, cut off the piece with a hack saw, and ground the ends round. After I had made all four pieces (two port and two starboard), I polished then up on a buffing wheel.
The next time I got to the boat, I bolted the four parts I made to the bow; the lowest hole in each piece to the bolt that passes through the roller and the second hole to the existing retaining pin hole. I stuck the stainless rod through the topmost holes in each pair passing through the hole in the anchor between and marked the required length of the two retaining pins. I cut the rod to lenght then drilled a 5/32" hole through one end for the retaining ring and another through the other end for the safety pin.
I now have two oversized anchors nicely pinned to the bow of the boat.
1988 Crealock 34