These are the various IMP PERM files I can find on this server.
perms early pdp11-45.pdf - Perms for an early PDP11/45 Imp compiler that were placed in-line in a program.
http://gtoal.com/athome/edinburgh/APM-gdmr/FMACS/IMPPERM.ASM
http://gtoal.com/athome/edinburgh/APM-gdmr/I/GGPERM.imp
http://gtoal.com/athome/edinburgh/APM-gdmr/I/PERM19C.imp
http://gtoal.com/athome/edinburgh/APM-gdmr/I/PERM20C.imp
http://gtoal.com/athome/edinburgh/APM-gdmr/I/VPERM19.imp
http://gtoal.com/compilers101/new-imp-to-c/.backup/perms.inc
http://gtoal.com/compilers101/new-imp-to-c/include/imp/perms.inc
http://gtoal.com/compilers101/new-imp-to-c/tests/imp2021/stdperm.imp
http://gtoal.com/compilers101/pdp15-imp/ORIG/gperm+tables.i15
http://gtoal.com/imp77-in-C/DevRelease0.3/stdperm-updated.imp
http://gtoal.com/imp77-in-C/stdperm.imp
http://gtoal.com/src/imp2c/PREVIOUS-imp2c/TESTS/stdperm.imp
http://gtoal.com/history.dcs.ed.ac.uk/archive/languages/imp11-tmp/earlyimp11/permsrc.asm
http://gtoal.com/history.dcs.ed.ac.uk/archive/languages/imp77-tmp/abd/STDPERM.IMP
http://gtoal.com/history.dcs.ed.ac.uk/archive/languages/imp-pdp15/gperm.i15
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/dec10/imp/perms.imp
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/deimos/ercm09/emas-2900/b_deimosperm.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/deimos/ercm09/emas-2900/newperm.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/deimos/ercm09/emas-2900/sys_perm2s.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/deimos/new/perm2s.asm
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/emas/users/ecslib/emas-2900/iperm.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/emas/users/ecslib/emas-a/impis-unpacked/intperms.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/emas/users/ercc07/emas-2900/ibm_iperm97s.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/emas/users/ercc07/emas-2900/minperms.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/emas/users/ercc07/emas-2900/muperms.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/mouses/.hidden/perms.cal
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/mouses/source-buggy/imp/perms.cal
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/mouses/source/imp/perms.cal
http://gtoal.com/history.dcs.ed.ac.uk/archive/os/vax-vms/adc/necce/perm.imp
http://gtoal.com/history.dcs.ed.ac.uk/archive/sm/EMAS/ecsc03/emas-a/impil_intperm.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/sm/EMAS/ecsc03/emas-a/impis_intperm.txt
http://gtoal.com/history.dcs.ed.ac.uk/archive/staging-area/EDINBURGH_REUNION/imp77-vax/lib/perm.mar