Yes, per the manufacturer the Chapin 7-inch Complete Pump Assembly 3012423 will work in the Chapin sprayer model 3102.
Per Chapin, the Chapin 7-inch Complete Pump Assembly 6-4620 should fit your sprayer number 3103. The thread should fit it but the handle will be different than the original on your sprayer.
The Chapin 7-inch Complete Pump Assembly 6-4620 is specifically designed for Chapin sprayers model 1180, 1253, 1255 and 1280, and 1288. We are not familiar with the ace brand line you mentioned and would recommend you contact Chapin directly so they can confirm if that is compatible with Chapin 7-inch Complete Pump Assembly 3012423. Chapin can be reached at 1-800-950-4458.
Per the manufacturer Chapin 7-inch Complete Pump Assembly 3012423 is specifically designed for Chapin sprayers model 1180, 1253, 1255 and 1280 only.
You can contact Chapin directly to see which part would work with your specific model.
Chapin-1800-950-4458