JFTR, 1363821 is the USA part number for the wiper switch, you really want a 1363820 which was fitted to non-USA 245s from year models 1979 to 1991.
If you luck out on finding some good HT-168 OE speakers, you can get some 4 inch Kenwood speakers from Ebay for about $50 the pair, which should fit in the existing speaker holes in the front doors. A few years ago, I gutted the dead Volvo speakers in this 244 I had, put the 20W RMS Kenwoods in the frames, remounted the speakers in the doors and put the OE grills over the top. Worked fine with the Volvo OE tape deck radio which would be lucky to put 15W RMS on a good day.