Hi Phil_Tijeras,
Getting a trailer and boat mated to each other can be a challenge and from experience might take a couple tries.
The OEM MacGregor trailer is somewhat unique compared to other typical trailers as you are well aware.
(Which for the life of me I can’t figure out why someone would steal that type of trailer….

… not much other than a Mac is gonna fit to it… that might help the cops find who took it…. Major Bummer! Sorry about your loss!)
We have a Mac26X and a PO mated it to a Sea Lion tandem axle galvanized trailer with four long bunks.
It works well for us but is higher up in altitude than the OEM arrangement by about a foot or more.
This requires us to comparatively go in further when launching/retrieving which hasn’t been an issue on the ramps we’ve (used but could be if using a very shallow one or beach launching) to get Over Easy to float off.
It may take a few “try-on’s” to get things properly adjusted so plan on it taking some time, tools and hopefully not a busy single lane ramp without a pier to tie off to between iterations.
When we replaced the trailer for our 15 ft runabout Scrambled to a ShoreLander single axle trailer that had been previously carrying a Grady White it took about a full day to pre-emptively statically adjust the trailer to the boat weight, center of gravity (CG) and hull shape/dimensions so we’d be in the general ballpark when it came to the “wet fitting”. If you have to move the axles fore/aft to get the tongue weight set (CRITICAL ASPECT for safe towing) it’s a whole lot easier when the boat isn’t on the trailer. We had to move our axle about a foot and a half from where it had been. We also inspected/replaced the tires as well as disassembled, cleaned, inspected and regressed both axle hubs at this time. We took advantage of the opportunity to scrap out the old trailer electrical wiring and lights to replace with new HD wiring and LED waterproof lighting and side markers. Again, a lot easier to do with an empty trailer.
This saved us a lot of hassle at the ramp which we were able to utilize off-season and mid-week. Even then we still had to contend with other boaters needing to launch/retrieve a couple of times. So we tried to minimize our ramp occupancy time and we were able to tie on to the end of the pier between iterative adjustments. In our case we were fortunate that the pre work only left us with relatively minor adjustment to the Bunks (to be moved in/out from centerline) and the front post moved (fore/aft) to fit the hull contours. Our “new” trailer had an adjustable sliding tongue bolted beam so fine tuning the hitch tongue weight wasn’t much hassle for us. The “wet fit” aspect took about four iterations and about as many hours…. We were fortunate in that we’d done this before, knew what to expect/do and brought all the tools/support equipment needed.
The results were very well worth it to have a properly fitted mating of boat and trailer that tows great with easy launch/retrieve characteristics.
At a minimum the hitch tongue weight needs to be no less than 10% of the combined trailer & boat weight as loaded for road travel.
Less than that minimum can/will result in fishtailing at highway speeds which can be extremely hazardous to not only you, your tow vehicle, boat trailer but also to the innocent others sharing the road with you. Not something to be taken lightly.
Hope this helps some in your efforts to find and fit your replacement trailer.
Best Regards,
Over Easy
