These boards are available (unstuffed), with the LM4500 chip, for $33.USD, or stuffed for $129. USD. Please send an email to firstname.lastname@example.org and I’ll give you instructions on how to order. I prefer payment via Paypal. There’s no problem with international shipping.
The recommended parts can be purchased from Digi-Key or Mouser. Please see the “Building” page for the parts list. Feel free to substitute, the only really critical parts are the ones in the oscillator (C3), as per notes in the LM4500 data sheet. You can also use high quality film caps mounted off the main board for the 3 caps (C1, C10, C11) in the audio path.
Here’s the new double sided board, stuffed, top, and bottom views -