As long as it fits inside the can the OD is not as important as the height and the inner diameter. Most of the IDs are large enough and should not be an issue - but you do need to make sure the one you decide on is able to fit over the center pipe yet not be so large it won't sit or stay on the bottom nut or seat on the pipe. The spring and washer assy has to be able to push against the filter top to keep the center sealed and filter seated on the bottom so the fluid is forced to go thru the filter and not around it.
According to packards1, the original 52-4 filter was 2 1/2 inches tall. I don't know if you will find a modern filter that tall but if not or the spring won't stretch to get the washer closer you can make a spacer out of a PVC pipe nipple or similar to go over the filter and have the spring compress and seal the spacer against the filter top. If the center turns out to be too large and filter wants to slip over the bottom seat you can use a thin flat washer under the filter for a wider support.
Here is an old thread giving a few filter numbers and links. Note that the pump is the shorter 55-6 pump but I believe the 52-4 pipe and bottom seat is similar so filters should fit the earlier too. You may need the spacer if the spring won't stretch. The thing to watch out for is what happened on the filter in the thread. When I took pump apart the filter element had separated from the center mesh and slipped down so the metal center at the top was exposed and fluid was completely bypassing the filter.
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