I didn't want to give you false hope as those parts could come up for sale next week or next year or later. It is hard to tell when it may show up.Parts for these old Model A-34 Jig Saws do come up for sale occasionally.
As for making a replacement, the Hold Down Lock Cylinder P/N 134-34 may not be difficult to replicate. It is as the name says a cylinder with a hole for the Hold Down Support Assembly P/N 134-40X to go through and a threaded hole coming from the end to lock the Hold Down Support Assembly with a threaded lever. The Hold Down Lock Lever P/N 23 could be fabricated out of a piece of metal rod, cutting threads on one end, add a washer with threads to lock it to the level or weld a washer there and bend the lever to shape. You would just need the measurements which I can get for you from the Jig Saws I have. It may be over a week before I can get them for you since I will be out of town. If I get a chance before I'll try to post them. The parts look as shown in the page of the Owner's Guide below.
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