Damaging the PIC should not be possible through the MIDI IN. The 6N13x Optocoupler is there to prevent this scenario. Inside the IC there is an optical connection, this way there is no direct electrical connection.
You can buy the pcb at:
SmashTV
Mikes Midishop
For parts you can try reichelt, musikding, banzaimusic.
The only tricky part is the OPL3 chipset. You can try on ebay. Maybe someone has a trusted source?
As a general rule of thumb; when a component is broken, it's better to use the wire cutter method as Peter described. It's much easier that way to get components out without damaging the pcb.
Look at the example on the wiki: http://www.ucapps.de/midibox_sid/mbsid_aout_interconnections.pdf
The correct names are there, just use J19 in case of the LPC17.
My suggestion would be:
check the interconnection between baseboard and CS with multimeter
check correct placing of resistor networks
check soldering of the 74HC165 sockets
I had a similar problem. Updated the bootloader on my Seq4L after that no ports were available in MIOS Studio. I fixed it by removing the usb midi driver completely.
You could do that. Beware that it runs under CygWin. So you still have to do linux commands. Might be cheaper and more flexible to make a virtual machine with Ubuntu 12.04. There are a lot of tutorials available.
I found the code googling a bit. Take me a bit of effort to get it working. I think there is a plugin for IPB so that it is possible todo it the easy way.