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WILLIAMS makes an aperture sight that fits onto the m/96 Swede ladder base. The manufacturers suggested cost is $25 and it replaces the ladder sight with no drill and tap required.
I bought one a couple of weeks ago at a Gun Show for a $20 bill.
You might look on E-Bay for a Vasterras micrometer rear sight, or a F-ram AGJ micrometer sight, but they are open sights, not peep.
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