Technobeam LAD

Has anyone ever tried to build a replacement Laser for the Technobeam vs. spending over $300 to purchase the replacement? I have some Technobeams that do not have the LAD option but I would like to add it as I use them on occasion in high ambient light conditions & it would be very helpful if I knew where the beam was prior to opening the shutter. But spending $300 dollars on a 4.95mw laser is a rip off. Has anyone ever tinkered with an alternative since you can buy a 4.95mw laser diode on eBay for next to nothing? Thanks!
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