I actually dev a project called LANCommander which can be used as a sef-hosted digital game distribution platform ala Steam, Epic Games, etc. It has built in support for redistributables. What i would actually do is make the DOSBox/Win98 combo a redist and then have the individual games require that redist.

That way if you wanted to make changes like install patches on Windows or change the DOSBox config you only have to do it to the redist.