Maximum amount of spacecrafts:
H&C 101: 500
H&C 201: 500
H&C 301: 500
BX 7: 500
BX 8: 500
BX 9: 500
Muller 400: 500
Muller 404: 500
Muller 408: 500
VF-56: 500
VF-66: 500
And finally
VF-76: 500
Total: 6000 spacecrafts. If uncommon items count as a unique one, then multiply this result by 4.