Canon FD focal-reduced adapter
https://www.ebay.com/itm/405328568587

Primes

[the Canon 24mm adapts to about 17mm, so not worth buying a manual lens in that focal length]
https://digital-photography-school.com/laowa-17mm-f-1-8-lens-review-micro-four-thirds/ (semi-compact, manual)
https://www.bhphotovideo.com/c/product/1860797-REG/yongnuo_yn17mm_f1_7m_yn_17mm_f_1_7m_lens.html (bulky but good, auto/manual focus switch)
https://www.mpb.com/en-us/product/voigtlander-nokton-17-5mm-f-0-95-micro-four-thirds-fit (spendy)
https://www.mpb.com/en-us/product/7artisans-18mm-f-63-ii-micro-four-thirds-fit (lomo body cap)
-- https://www.mpb.com/en-us/product/panasonic-lumix-g-14mm-f-2-5 (compact)
https://www.mpb.com/en-us/product/olympus-m-zuiko-digital-17mm-f-2-8 (affordable)
!- https://www.mpb.com/en-us/product/panasonic-lumix-g-20mm-f-1-7-asph (gold standard)
[23-28mm duplicates my Industar, so another one would have to be faster or autofocus]
https://www.bhphotovideo.com/c/product/1675250-REG/ttartisan_a35bs_m43_23mm_f_1_4_aps_c_lens.html
Meike - manual focus but solid and inexpensive
-- https://www.adorama.com/mk2518mft.html
https://www.mpb.com/en-us/product/voigtlander-nokton-25mm-f-0-95-micro-four-thirds-fit
https://www.mpb.com/en-us/product/olympus-m-zuiko-digital-ed-25mm-f-1-8 (compact)
!- https://www.mpb.com/en-us/product/panasonic-lumix-g-25mm-f-1-7-asph (bulkier but cheap, even new)
https://www.mpb.com/en-us/product/sigma-30mm-f-2-8-dn-art-micro-four-thirds-fit (compact)
-- https://www.mpb.com/en-us/product/panasonic-lumix-g-macro-30mm-f-2-8-asph-mega-o-i-s ~$200
Olympus 30mm f3.5 macro ~$180
[35mm duplicates my 50mm Canon 1.8, so not smart to get as a manual lens]
https://7artisans.store/products/7artisans-35mm-f1-4-apsc (bargain & retro)
https://www.bhphotovideo.com/c/product/1450519-REG/meike_mk35f1_7m3_4_mk_35mm_f1_7_lens_for.html
-- https://www.mpb.com/en-us/product/olympus-m-zuiko-digital-ed-45mm-f-1-8
-- Panasonic 45mm f1.7 ~$200
https://www.mpb.com/en-us/product/rokinon-85mm-f-1-4-as-if-umc-micro-four-thirds-fit

Zoom

Telephoto
https://www.mpb.com/en-us/product/panasonic-lumix-g-vario-45-150mm-f-4-5-6-asph-mega-o-i-s (similar size to 12-60)
-- https://www.mpb.com/en-us/product/panasonic-lumix-g-vario-35-100mm-f-4-5-6-asph-mega-o-i-s (compact, not cheap)
?- https://www.mpb.com/en-us/product/olympus-m-zuiko-digital-ed-40-150mm-f-4-5-6-r (cheap!)
General/close
?- https://www.mpb.com/en-us/product/tamron-14-150mm-f-3-5-5-8-di-iii-micro-four-thirds-fit (cheaper alternative to Lumix superzoom in f/3.5, narrower body)
https://www.mpb.com/en-us/product/panasonic-lumix-g-vario-12-60mm-f-3-5-5-6-asph-power-o-i-s
-- https://www.mpb.com/en-us/product/olympus-m-zuiko-digital-ed-12-50mm-f-3-5-6-3-ez (slimmer & cheaper than Lumix 12-60, but longer)
https://www.mpb.com/en-us/product/panasonic-lumix-g-x-vario-12-35mm-f-2-8-asph-power-o-i-s (a bit spendy but fast)
Pancake version:
-- https://www.mpb.com/en-us/product/panasonic-lumix-g-vario-12-32mm-f-3-5-5-6-asph-mega-o-i-s (often sold with Lumix body)
Mid-size:
https://www.mpb.com/en-us/product/panasonic-lumix-g-vario-14-42mm-f-3-5-5-6-ii-asph-mega-o-i-s

Adapted

FD:
Canon 35mm f2.8, ~$140!
Tokina 28mm f2.8, $40; Tamron, others
Canon FL 35mm f2.5 (duplicates Industar 28, common zooms)
Canon FD 35-70mm f3.5 zoom (inexpensive, compact)
Canon FD 28-85mm F4 zoom (bulkier, but macro capable)
Canon 100mm f2.8 ($ compact, not macro)
Canon FD 35-105mm (also midsize, most have flared end)
Tokina 80-200 zoom (compact; Dad has big Vivitar zoom in similar range)
-- Tamron 28-200 (plastic but versatile)
Quantaray 28-70 f2.8
-- Sigma 35-70 f2.8
! Tamron 35-105 f2.8
--Tamron/Sigma/et.al. 28-70 f3.5 zoom (compact)
-- Tamron 90mm macro (Sigma is tiny but $)

C-mount:
Cosmicar 16mm, 25mm (tiny); zoom
Computar? 12mm, 16mm, 25mm (has the right aesthetic)
Pentax
-- Sony cine zoom, matte aluminum
-- Industar/KMZ Soviet cine lenses; Meteor zoom?
-- other brands: Bell & Howell, Wollensak, etc. (cool metallic cine lenses)

M42/L39:
Carl Zeiss Jena 35mm f2.8, $80+
! Industar/KMZ: 28mm, 50mm pancakes; 35mm & 58mm much more expensive, but Helios 44 is revered
! Jupiter 8 50mm L39