StarTech
Your measurements are correct (3/4 x 1-3/8) and there are no common bearings with such measurements... not even in the metric world.
A possible solution is bearing 6003 (17 x 35 x 10mm), but you have to rough 2.05mm on the axle, place a shim on the side of the wheel, change the "C" clamp and make a spacer between the inner and outer bearing.
The most difficult thing is to rough 2.05mm on the axis that has a curve.
This metric bearing costs USD 20.00 with 10 units here.
If I buy this XIKE, 4 units costs USD 13.99 + 21.87 (shipping) + taxes in my country and it still takes 27 business days (by ebay).
Order Summary by Amazon: $11.99 + Shipping and Handling: $16.68 + Deposit for import fees:: US$ 27.09
Order total: $55.76
In the end, each bearing costs US$13.94.