Digital and analog alignment disks are still available from Accurite at
accurite.com.
What I was trying to say is that mechanical alignment fixtures are not practical across the range of 5.25" 3.5" or 8" floppy drives. You need to use a oscilloscope OR a digital alignment tester along with a analog alignment disk to align floppy disk drives. The replacement for oscilloscope when aligning a floppy disk drive was/were digital alignment testers. Unfortunately, as far as I know, no digital alignment testers are currently in production. The ones that I have and use costed between $400-$1500 when they were in production. Given the small demand for new digital alignment testers, the possibility of new, low quantity production at a lower, more attractive price for hobby people is doubtful.
The least expensive way to get small quantities of floppy drive serviced is probably to take them to a professional. If you insist on trying to repair and align floppies yourself, you need a decent quality 100mhz (minimum) dual trace oscilloscope You could find a working one on eBay between $100-$300. You might find one that needs work if you are willing to learn how to fix it for $0-$50. Then, I recommend a drive exerciser to control the floppy drives. You might find a used one for between $15-$50 on eBay. And lastly, you will need some alignment disks, $65 for 3.5", or 5.25" or $200 for an 8" alignment disk.
If you want the more modern hardware solution, look for an alignment tester on eBay. They crop up occasionally on eBay for between $50-$250. Look for a Lynx Technology Alignment Tester. The Model 460 and 475 are the more advanced units.