You used to be able to purchase “Pad Saws”.
Most pad saws were basically handles into which you could insert hacksaw or woodsaw blades of similar dimensions, and lock the blades in place with a screw.
Shorter blades could generally be used if you wanted to make the saws more compactly storable.
Bosch used to make a metal and plastic version made to take their T-shank jigsaw blades and reciprocating saw blades. Bosch discontinued the older midel, but I think they still make a metal version that sort of looks like a box cutter, it may only be sold in the Europe though, or thru Amazon/Ebay from sellers in Europe.
Otherwise, Joseph Marples, a British tool brand( not the Irwin one), still manufactures Oad saws with a turned wood handle, and brass blade holder. The design probably goes back a century or more.
The saws aren’t as readily available in the USA, but might be available from fine woodworking tool sources as well as Ebay and thru antique dealers. If the handle needs to be more compact the sides could probably be planed or sanded down.
Eclipse is another British tool brand that makes a pad saw handle.
I think the handles are made from a cast zink alloy.
The current version is the 70-130R.
It has two blade positions. a pistol grip and a straight grip position.
The current version uses a slot head screw
Older Eclipse pad saws only had the straight blade position, but the saws used a knurled thumb screw, so were better for pocket carry.
I think the Eclipse saw may not be officially sold in the USA, but you can usually purchase them new thru ebay or Amazon.
The older version are usually available thru ebay from US and British sellers.