Deleting specific frames with avisynth

I have a video - a DVD transfer of a 8mm silent audience film of a rock concert. I have noticed that the frame structure is pretty strange, you have 3 or 4 progressive frames followed by one frame, which is a "combination" of the frame before and the frame after.

E.g.  frame 363 is a "normal" progressive frame, frame 364 is a "normal" progressive frame, frame 365 is a combination of frames 364 and 366, frame 366 is again a "normal" progressive frame.

The list of the "garbage" frames is pretty repeatable :

365 369 372 375 378 381 384 388 391 395 398 401
405 408 412 415 418 422 425 428 432 435 438 441
445 448 452 455 458 461 465 468 471 474 478 481
485 488 491 495 498 501 505 508 511 515 518 521
525 528 532 535 538 541 545 548 551 554 558 561
564 568 571 574 578 581 584 588 591 595 598 601    

etc.

The concert footage starts with frame 361, frames 0-360 are just the "intro" (not sure what's the correct english word).

I am looking for an automatic way (e.g. AviSynth) to do "something" with these frames, at least deleting them.  The video is PAL, 25 progressive frames per second.

Any help ?

I've been thinking about using SelectEvery() but the resulting script would be pretty complicated :-) I would actually need something like "DeleteEvery()" if such thing exists :-)

Thanks for the Deblend tip, it looks pretty interesting