Every respectable army on campaign requires a bridging train. I have always been keen on impedimenta and reproducing them on the table top. I think my obsession with pontoons and bridging may have started with reading C.S. Forester's Death to the French, the story of a lone Rifleman in the Peninsular War (and the equal of Forester's The Gun.)
The link to Vintage Wargaming is that my pontoon train to date has been three Hinchliffe 25mm pontoon wagons, a David Clayton-produced Hinton Hunt pontoon wagon without a pontoon, and a Fine Scale Factory French Pontoon wagon. All these (apart from the Hinton one) are 25mm.Two of the Hinchliffe wagons came from Terry Wise.
These have been done using an ingenious basing system - the wagon on one base, which is then glued on top of a second, double length base. The team (oxen, I think Jacklex) are then on a second base the same size as the wagons, but not attached to the long base underneath. This means they can be removed to be used with other equipment, swapped for horse teams etc. The final Hinchliffe wagon was a purchase from e-bay, with a horse team of S Range draught animals. Four are attached to the base, with a further three on a second base, to provide additional traction as required.
Definitely not vintage, but very useful, are the new French Pontoon Wagon sets which have just been released bu HaT in 1/72 and plastic. Each box contains parts for three wagons, and materiel (a pontoon and four roadway sections each)which can either be stacked on a loaded wagon, or assembled as bridge units. They are very cleverly designed to come apart and be reassembled, but given the cost it would be easier just to buy two boxes, one in each configuration. But NB,this may not be obvious, you need a box of the HaT French Napoleonic limbers to provide the front axles and teams.
These wagons could easily serve from 1700 up to the mechanized area (1930s or so) and possibly beyond.