Thanks to the OP, who followed through on this "thread." Following Bulldog's suggestion, the link below describes the outcome, so that we have it available in origin thread.
viewtopic.php?p=323674#p323674I'll just add that hardware stores often have small machine parts in common standard forms, so screws of this spec could be purchased in smaller quantities.
As a historical point if I remember correctly, Martin's fly reel manufacturing was part of a much larger production range in Utica, N.Y. that included volume supply of a range of standard machine parts.
The OP probably knows this, but for others who might be replacing a screw or reassembling a pillar and plate reel, Pfluegers and Martins being the classics of industrial chic design and manufacture.
Use the mild form, tool-release Loctite or a home handyhack: "nylock" substitutes such as a shred of
plastic wrap or a piece of fine tippet material; or a drop of nailpolish on the threads.
Assemble the reel with all screws just shy of snug. Then use an approximate crisscross pattern, both side to side and clockface position, to snug the screws sequentially. Do this in increments, maybe two or three passes around the reel, until each screw is snug and won't tighten further without excessive force. If all are snugged down in this pattern, only comfortable tightening within the limits of a small, well-fitting screwdriver (ideally, a gunsmithing type) is needed. No mangled slots or cratches from slipping. Small screw drivers have small grips for a reason. If using a screwdriver with a full size grip, avoid driving that little 3-48 like it is a large self-tapping wood screw going into a piece of oak.