My son recently turned three years old. Using an Enid Gilchrist pattern (which appears in a number of her pattern books in the 50s, 60s and 70s) I made this shirt with raglan sleeves and what was essentially a shawl collar. It was fun to custom make it- I used a poplin with little cars all over it with red buttons to match his slacks- I very much enjoyed see him wearing it on a recent play date.
Admittedly, I didn’t find the shawl collar easy but I stumbled on this tip sheet by Marian Corey (whom I have previously waxed lyrical about)… just in case anyone else is looking for tips and tricks for a similar garment! Good luck…. hope this is helpful.