On Wednesday, March 26, 2014 12:47:08 AM UTC-7, Van Henson wrote:

...Over the manufacturer's name is the marking "1345-2"
and elsewhere the size designation "4 1/2 Jx13H2" and
still elsewhere the designator "ET27". It has a four
lug pattern; I haven't measured the center-to-center
distance on the lug holes...

Unfortunately, you don't yet have all the information you need to get a replacement. What we can tell is:

"4 1/2 Jx13H2" means that the wheel is for 13" tires and that the width of the wheel is 4.5". I don't remember what the J is for (I think it refers to the type of construction), and I don't know what the H2 means. I have no idea what ET27 is; probably a proprietary manufacturer part number or descriptor.

What you need to know to get a matching replacement is:

Diameter where the tire seats (we know it is 13")
Width between the tire bead retaining flanges (we know it is 4.5"
Bolt circle (not known)
Offset (not known)

The bolt circle is best measured with the plastic gauges that they have at junkyards. Bring one of your current wheels with you and have them measure it.

To get the offset, you need to do some measuring to find the distance between the plane of the wheel's mounting surface and a plane that is halfway between the two tire-retaining flanges. Since you know that the width is 4.5", you can also measure the backspacing to determine the offset. I'd suggest you google "backspacing" and go from there.

Thanks, Bob K.